This document provides an introduction to basic navigation concepts including:
1) Navigation enables locating one's position and traveling between places using tools like nautical charts, compasses, and coordinate systems of latitude and longitude.
2) Nautical charts depict water depths, hazards, and navigation aids to allow mariners to safely navigate coastal and ocean waters.
3) Key concepts in navigation include great circles, meridians, parallels, compass rose, cardinal and intercardinal directions, and units of measurement like nautical miles.
The document discusses various methods and instruments used for celestial navigation. It describes tools like the sextant, astrolabe, and octant that were used to determine position by measuring the angle between celestial objects and the horizon. It also discusses coordinate systems and modern GPS technology used for navigation.
The document discusses gyrocompasses and magnetic compasses. It describes gyrocompass theory including how gyroscopes maintain orientation to true north. It also discusses gyro error determination and correction. Magnetic compass theory is explained including variation, deviation, and magnetic compass error. Methods to determine gyro error and apply corrections are provided along with examples of solving for true course from other compass readings.
The document discusses basic navigation concepts including types of navigation such as coastal, celestial, and electronic navigation. It covers terrestrial coordinate systems including latitude, longitude, and datums. Charts are also discussed, specifically the Mercator projection which maintains true shape over small areas and allows accurate measurement of position, distance, and direction.
The document describes various navigational instruments and systems used on ships. It provides brief descriptions of instruments such as the gyrocompass, magnetic compass, radar, sonar, fish finder, Automatic Radar Plotting Aid (ARPA), Electronic Chart Display and Information System (ECDIS), Automatic Identification System (AIS), marine autopilots, rudder angle indicator, voyage data recorder, Global Positioning System (GPS), chart plotter, marine VHF radio, public address system, rate of turn indicator, close-quarters monitor, log, echosounder, radio altimeter, Long Range Tracking and Identification (LRIT) system, Global Maritime Distress and Safety System (GMDSS), anemometer
This document discusses various concepts relating to time and navigation. It begins by describing jet lag and how time is based on the relationship between Earth and the Sun. It then discusses chronometers, which are precision timekeeping devices used to determine longitude at sea. It also discusses ship's bells, which are rung to indicate half-hour and full-hour intervals, and various timekeeping systems used in the military such as the 24-hour clock. Finally, it discusses time zones and how to convert between zone time and Greenwich Mean Time.
1. The document discusses the operational use of radar and ARPA, including fundamental radar principles, safe distances, radiation hazards, radar components, factors affecting performance, and interpretation of radar pictures.
2. It describes how radar works by transmitting electromagnetic pulses that bounce off objects and return, allowing the distance to be calculated. On ships, radar is used for collision avoidance and navigation assistance.
3. Key factors that influence radar detection range and resolution are discussed, such as wavelength, antenna height, target size, weather conditions, and more. Interpreting radar images requires experience due to effects like radar shadows and multiple echoes.
An ECDIS is an electronic system that can display navigational charts and position information to serve as an alternative to paper charts. It integrates data from GPS, radar, and AIS to determine a vessel's position in relation to land, hazards, and navigation aids. The IMO requires all ships to carry electronic charts and ECDIS to meet chart carriage requirements. When planning a passage using ECDIS, the navigator must ensure the vessel has up-to-date chart licenses, enter vessel parameters, set the safety contour and domain, and create a route by placing waypoints while checking for hazards. ECDIS is then used during the voyage to monitor position and trigger alarms if safety parameters are exceeded.
This document provides guidance on chartwork and fixing conventions. It discusses:
1. Chartwork conventions such as position lines, tidal streams, clearing bearings, and position fixing methods.
2. Guidance on fixing positions including visual fixes using bearings, radar fixes using ranges, and horizontal sextant angle fixes.
3. Details on calculating tidal streams and estimating positions based on dead and estimated reckoning.
The document discusses various methods and instruments used for celestial navigation. It describes tools like the sextant, astrolabe, and octant that were used to determine position by measuring the angle between celestial objects and the horizon. It also discusses coordinate systems and modern GPS technology used for navigation.
The document discusses gyrocompasses and magnetic compasses. It describes gyrocompass theory including how gyroscopes maintain orientation to true north. It also discusses gyro error determination and correction. Magnetic compass theory is explained including variation, deviation, and magnetic compass error. Methods to determine gyro error and apply corrections are provided along with examples of solving for true course from other compass readings.
The document discusses basic navigation concepts including types of navigation such as coastal, celestial, and electronic navigation. It covers terrestrial coordinate systems including latitude, longitude, and datums. Charts are also discussed, specifically the Mercator projection which maintains true shape over small areas and allows accurate measurement of position, distance, and direction.
The document describes various navigational instruments and systems used on ships. It provides brief descriptions of instruments such as the gyrocompass, magnetic compass, radar, sonar, fish finder, Automatic Radar Plotting Aid (ARPA), Electronic Chart Display and Information System (ECDIS), Automatic Identification System (AIS), marine autopilots, rudder angle indicator, voyage data recorder, Global Positioning System (GPS), chart plotter, marine VHF radio, public address system, rate of turn indicator, close-quarters monitor, log, echosounder, radio altimeter, Long Range Tracking and Identification (LRIT) system, Global Maritime Distress and Safety System (GMDSS), anemometer
This document discusses various concepts relating to time and navigation. It begins by describing jet lag and how time is based on the relationship between Earth and the Sun. It then discusses chronometers, which are precision timekeeping devices used to determine longitude at sea. It also discusses ship's bells, which are rung to indicate half-hour and full-hour intervals, and various timekeeping systems used in the military such as the 24-hour clock. Finally, it discusses time zones and how to convert between zone time and Greenwich Mean Time.
1. The document discusses the operational use of radar and ARPA, including fundamental radar principles, safe distances, radiation hazards, radar components, factors affecting performance, and interpretation of radar pictures.
2. It describes how radar works by transmitting electromagnetic pulses that bounce off objects and return, allowing the distance to be calculated. On ships, radar is used for collision avoidance and navigation assistance.
3. Key factors that influence radar detection range and resolution are discussed, such as wavelength, antenna height, target size, weather conditions, and more. Interpreting radar images requires experience due to effects like radar shadows and multiple echoes.
An ECDIS is an electronic system that can display navigational charts and position information to serve as an alternative to paper charts. It integrates data from GPS, radar, and AIS to determine a vessel's position in relation to land, hazards, and navigation aids. The IMO requires all ships to carry electronic charts and ECDIS to meet chart carriage requirements. When planning a passage using ECDIS, the navigator must ensure the vessel has up-to-date chart licenses, enter vessel parameters, set the safety contour and domain, and create a route by placing waypoints while checking for hazards. ECDIS is then used during the voyage to monitor position and trigger alarms if safety parameters are exceeded.
This document provides guidance on chartwork and fixing conventions. It discusses:
1. Chartwork conventions such as position lines, tidal streams, clearing bearings, and position fixing methods.
2. Guidance on fixing positions including visual fixes using bearings, radar fixes using ranges, and horizontal sextant angle fixes.
3. Details on calculating tidal streams and estimating positions based on dead and estimated reckoning.
The document summarizes the history of navigation from ancient times to modern day. It describes how early navigators stayed close to shore and used landmarks to navigate before later developing tools like charts, quadrants, and astrolabes to determine latitude and longitude. Key advances included the invention of the chronometer to measure longitude in 1764 and modern technologies like radar, Loran, and GPS satellites that provide highly accurate global positioning. The overall progression showed how explorers improved navigation techniques and tools over time to trade, explore new lands, and spread religion more safely and efficiently around the world.
Compass errors arise from two sources: variation and deviation. Variation is the difference between magnetic and true north, while deviation is caused by nearby magnetic interference. Compass error is the sum of variation and deviation, representing the angle between true and compass north. Finding transit or gyro errors allows one to determine the compass error. Regular corrections are needed since errors change with location and vessel orientation.
The compass uses magnetic properties to show direction. It has a magnetic needle that points north because the Earth acts as a large magnet. The compass shows the four cardinal directions - north, south, east, and west - through initials on a compass rose diagram. It works because all magnets have two poles, and the north pole of the compass needle is attracted to the Earth's magnetic south pole. However, true north and magnetic north can differ slightly due to magnetic declination.
The document provides information on the components and operation of marine radar systems. It describes what radar can do, including navigating in darkness/fog and determining position. It outlines key components like the magnetron, transmitter/receiver switch, scanner, and display unit. It details radar controls and functions like range and gain adjustment. It explains concepts like relative and true bearings, resolution, interference, and target marking and tracking.
This document discusses the lost art of celestial navigation using the stars. It explains how sailors were able to determine their latitude and longitude at sea before modern navigation tools. Some key methods mentioned include using Polaris to determine latitude, observing the positions of stars near the eastern or western horizon over multiple nights to calculate longitude, and using a Mariner's Nocturnal instrument to determine local time by the angles between stars like Polaris and Ursa Major.
This document provides information about tides and tidal streams, including:
- The gravitational forces that cause tides from the Moon and Sun.
- How tides occur twice daily, with high and low waters approximately 6 hours and 10 minutes apart.
- How spring and neap tides occur depending on the Moon's position relative to the Earth and Sun.
- How to use Admiralty Tide Tables to calculate tide heights and depths at any location and time.
This document provides an introduction to key ship handling terms and commands for navigating a ship. It defines basic terms like bow, stern, port, and starboard. It outlines standard engine commands by speed range and rudder commands by degree or common term. Maneuvering commands are described that combine engines and rudders. Ship handling concepts of split-ship and twist maneuvers are introduced. Precise speed and course adjustments are also covered, along with mooring and the 3-2-1 distance rule for other vessels.
This document provides information for mariners on weather forecasting tools, weather patterns, air masses, fronts, clouds, and interpreting weather charts. It outlines various rules of thumb for mariners, such as pressure trends indicating weather changes and using Buys Ballot's law to locate high and low pressure systems. Common weather sayings are explained, such as how red skies at night or morning relate to approaching weather systems. Types of clouds and what they indicate are also defined.
Officers and Crew in the Deck DepartmentLourisa Loren
The document discusses the deck department onboard vessels. It describes the deck department as the organizational unit responsible for maintaining the ship's hull, cargo gear, accommodation, life saving and firefighting appliances. It outlines the roles of the master, chief officer, second officer, third officer, deck cadet, boatswain, able seaman, and ordinary seaman who make up the deck officers and ratings in the deck department. Their key duties are also summarized such as navigation, safety, cargo operations, and vessel maintenance.
This document provides information on basic navigation concepts. It defines navigation as the process of monitoring and controlling an aircraft from one place to another. Key aspects of navigation discussed include:
- Direction in terms of true, magnetic and compass headings, and how variation and deviation affect readings.
- Distance measurement using great circle routes versus rhumb lines. Great circles provide the shortest distance between two points on Earth.
- Time concepts such as GMT, time zones, and methods for converting between time zones.
- Altitude measurement using pressure altitude versus true altitude, and how instruments like the altimeter and barometer are used.
- Other navigational considerations like landmarks, checkpoints, speed, and factors needed
This document discusses various aspects of seamanship and marine navigation. It begins by defining seamanship as the art possessed by seafarers to safely operate ships at sea. Seamanship is evolutionary as skills are acquired over time through experience, and dynamic as the skills needed vary between roles and adapt with new technology. The document then discusses four main types of navigation: piloting, dead reckoning, celestial navigation, and radio navigation. It also defines key terms used in marine navigation like the prime meridian, nautical mile, magnetic north versus true north. The document provides diagrams and descriptions of the key parts of a research vessel and typical ship. It concludes by classifying ships according to their purposes and support types.
The document summarizes the key parts and rules of COLREGS (Convention on the International Regulations for Preventing Collisions at Sea). It is divided into 5 parts, with Part A covering general rules about application and responsibilities, Part B covering steering and sailing rules for vessels in sight of each other or any visibility condition, Part C covering lights and shapes, Part D covering sound signals, and Part E covering exemptions. Key rules discussed in Part B include safe speed, action to avoid collisions, narrow channels, traffic separation schemes, and specific rules on sailing vessels, overtaking, head-on, and crossing situations.
This document provides information about basic concepts related to charts used for aviation purposes. It discusses key terms like maps, charts, projections and distortions that occur when representing the spherical Earth on a flat surface. It also describes different types of projections including plane, conical, cylindrical and their characteristics. Specific projections like Mercator and Lambert Conformal are explained in more detail.
This document provides instructions for plotting radar targets over a 6 minute interval to determine course, speed, closest point of approach (CPA), and time to CPA (TCPA) of other vessels. It outlines the steps to mark initial bearing and range, draw target movement line, transfer own vessel movement, calculate distances traveled, and determine other vessel's course, speed, CPA and TCPA. It concludes that in this example, if no course or speed changes are made, there will be a collision at a CPA of 0.0 nautical miles at 12:09:48, and that the observer is the give-way vessel in a crossing situation.
A time diagram is a diagram on the plane of the celestial equator that shows the celestial equator as a circle with celestial meridians and hour circles as radial lines. It is used to solve time problems and other problems involving arcs of the celestial equator or angles at the pole by showing the relationships between quantities like hour angles, longitude, and units of time. On the diagram, the Greenwich meridian is at the top with east longitudes to the right and west longitudes to the left as viewed from the south pole.
A presentation on 'The International Convention for Preventing Collisions at Sea 1972' (COLREG 72) to the LLM Maritime Law students at University of Southampton.
A ship's crew is divided into three main departments: the deck department oversees navigation and cargo operations; the engineering department maintains machinery and systems; and the steward's department is responsible for catering. Each department has a well-defined hierarchy and roles, from the captain and chief engineer down to more junior crew members, with areas of responsibility that are integral to the safe and efficient operation of the vessel.
The International Code of Signals uses a system of maritime signal flags to communicate messages between ships. Individual flags can represent letters to spell out words, have standard predefined meanings, or form code words that are looked up in a shared code book. Flags are also used in yacht and dinghy racing to convey specific instructions like an impending start or course changes.
The document provides an overview of key rules and definitions from the Navigation Rules for Marine Law Enforcement Officers. It defines terms like vessel, underway, power-driven and sailing vessels. It outlines lighting requirements and sound signals. It discusses rules for determining risk of collision, taking action to avoid collision, operating in narrow channels, overtaking situations, head-on encounters, and crossing situations.
1) The document discusses celestial navigation techniques, including methods for determining speed, direction, and position using various historical instruments.
2) Key instruments mentioned include the sandglass, log, compass, lead, astrolabe, cross-staff, back-staff, quadrant, octant, chronometer and sextant.
3) The document also covers the three coordinate systems used in celestial navigation: terrestrial, celestial, and horizon. It provides examples of how sights are reduced using the Nautical Almanac and tables to determine position.
This document provides an overview of various navigation systems used in aviation, including Non-Directional Beacon (NDB), Automatic Direction Finder (ADF), VHF Omni-directional Range (VOR), Distance Measuring Equipment (DME), Instrument Landing System (ILS), marker beacons, radar, Global Positioning System (GPS), and approach lighting. It describes what each system is, how it functions, and its purpose in aiding pilot navigation.
The document summarizes the history of navigation from ancient times to modern day. It describes how early navigators stayed close to shore and used landmarks to navigate before later developing tools like charts, quadrants, and astrolabes to determine latitude and longitude. Key advances included the invention of the chronometer to measure longitude in 1764 and modern technologies like radar, Loran, and GPS satellites that provide highly accurate global positioning. The overall progression showed how explorers improved navigation techniques and tools over time to trade, explore new lands, and spread religion more safely and efficiently around the world.
Compass errors arise from two sources: variation and deviation. Variation is the difference between magnetic and true north, while deviation is caused by nearby magnetic interference. Compass error is the sum of variation and deviation, representing the angle between true and compass north. Finding transit or gyro errors allows one to determine the compass error. Regular corrections are needed since errors change with location and vessel orientation.
The compass uses magnetic properties to show direction. It has a magnetic needle that points north because the Earth acts as a large magnet. The compass shows the four cardinal directions - north, south, east, and west - through initials on a compass rose diagram. It works because all magnets have two poles, and the north pole of the compass needle is attracted to the Earth's magnetic south pole. However, true north and magnetic north can differ slightly due to magnetic declination.
The document provides information on the components and operation of marine radar systems. It describes what radar can do, including navigating in darkness/fog and determining position. It outlines key components like the magnetron, transmitter/receiver switch, scanner, and display unit. It details radar controls and functions like range and gain adjustment. It explains concepts like relative and true bearings, resolution, interference, and target marking and tracking.
This document discusses the lost art of celestial navigation using the stars. It explains how sailors were able to determine their latitude and longitude at sea before modern navigation tools. Some key methods mentioned include using Polaris to determine latitude, observing the positions of stars near the eastern or western horizon over multiple nights to calculate longitude, and using a Mariner's Nocturnal instrument to determine local time by the angles between stars like Polaris and Ursa Major.
This document provides information about tides and tidal streams, including:
- The gravitational forces that cause tides from the Moon and Sun.
- How tides occur twice daily, with high and low waters approximately 6 hours and 10 minutes apart.
- How spring and neap tides occur depending on the Moon's position relative to the Earth and Sun.
- How to use Admiralty Tide Tables to calculate tide heights and depths at any location and time.
This document provides an introduction to key ship handling terms and commands for navigating a ship. It defines basic terms like bow, stern, port, and starboard. It outlines standard engine commands by speed range and rudder commands by degree or common term. Maneuvering commands are described that combine engines and rudders. Ship handling concepts of split-ship and twist maneuvers are introduced. Precise speed and course adjustments are also covered, along with mooring and the 3-2-1 distance rule for other vessels.
This document provides information for mariners on weather forecasting tools, weather patterns, air masses, fronts, clouds, and interpreting weather charts. It outlines various rules of thumb for mariners, such as pressure trends indicating weather changes and using Buys Ballot's law to locate high and low pressure systems. Common weather sayings are explained, such as how red skies at night or morning relate to approaching weather systems. Types of clouds and what they indicate are also defined.
Officers and Crew in the Deck DepartmentLourisa Loren
The document discusses the deck department onboard vessels. It describes the deck department as the organizational unit responsible for maintaining the ship's hull, cargo gear, accommodation, life saving and firefighting appliances. It outlines the roles of the master, chief officer, second officer, third officer, deck cadet, boatswain, able seaman, and ordinary seaman who make up the deck officers and ratings in the deck department. Their key duties are also summarized such as navigation, safety, cargo operations, and vessel maintenance.
This document provides information on basic navigation concepts. It defines navigation as the process of monitoring and controlling an aircraft from one place to another. Key aspects of navigation discussed include:
- Direction in terms of true, magnetic and compass headings, and how variation and deviation affect readings.
- Distance measurement using great circle routes versus rhumb lines. Great circles provide the shortest distance between two points on Earth.
- Time concepts such as GMT, time zones, and methods for converting between time zones.
- Altitude measurement using pressure altitude versus true altitude, and how instruments like the altimeter and barometer are used.
- Other navigational considerations like landmarks, checkpoints, speed, and factors needed
This document discusses various aspects of seamanship and marine navigation. It begins by defining seamanship as the art possessed by seafarers to safely operate ships at sea. Seamanship is evolutionary as skills are acquired over time through experience, and dynamic as the skills needed vary between roles and adapt with new technology. The document then discusses four main types of navigation: piloting, dead reckoning, celestial navigation, and radio navigation. It also defines key terms used in marine navigation like the prime meridian, nautical mile, magnetic north versus true north. The document provides diagrams and descriptions of the key parts of a research vessel and typical ship. It concludes by classifying ships according to their purposes and support types.
The document summarizes the key parts and rules of COLREGS (Convention on the International Regulations for Preventing Collisions at Sea). It is divided into 5 parts, with Part A covering general rules about application and responsibilities, Part B covering steering and sailing rules for vessels in sight of each other or any visibility condition, Part C covering lights and shapes, Part D covering sound signals, and Part E covering exemptions. Key rules discussed in Part B include safe speed, action to avoid collisions, narrow channels, traffic separation schemes, and specific rules on sailing vessels, overtaking, head-on, and crossing situations.
This document provides information about basic concepts related to charts used for aviation purposes. It discusses key terms like maps, charts, projections and distortions that occur when representing the spherical Earth on a flat surface. It also describes different types of projections including plane, conical, cylindrical and their characteristics. Specific projections like Mercator and Lambert Conformal are explained in more detail.
This document provides instructions for plotting radar targets over a 6 minute interval to determine course, speed, closest point of approach (CPA), and time to CPA (TCPA) of other vessels. It outlines the steps to mark initial bearing and range, draw target movement line, transfer own vessel movement, calculate distances traveled, and determine other vessel's course, speed, CPA and TCPA. It concludes that in this example, if no course or speed changes are made, there will be a collision at a CPA of 0.0 nautical miles at 12:09:48, and that the observer is the give-way vessel in a crossing situation.
A time diagram is a diagram on the plane of the celestial equator that shows the celestial equator as a circle with celestial meridians and hour circles as radial lines. It is used to solve time problems and other problems involving arcs of the celestial equator or angles at the pole by showing the relationships between quantities like hour angles, longitude, and units of time. On the diagram, the Greenwich meridian is at the top with east longitudes to the right and west longitudes to the left as viewed from the south pole.
A presentation on 'The International Convention for Preventing Collisions at Sea 1972' (COLREG 72) to the LLM Maritime Law students at University of Southampton.
A ship's crew is divided into three main departments: the deck department oversees navigation and cargo operations; the engineering department maintains machinery and systems; and the steward's department is responsible for catering. Each department has a well-defined hierarchy and roles, from the captain and chief engineer down to more junior crew members, with areas of responsibility that are integral to the safe and efficient operation of the vessel.
The International Code of Signals uses a system of maritime signal flags to communicate messages between ships. Individual flags can represent letters to spell out words, have standard predefined meanings, or form code words that are looked up in a shared code book. Flags are also used in yacht and dinghy racing to convey specific instructions like an impending start or course changes.
The document provides an overview of key rules and definitions from the Navigation Rules for Marine Law Enforcement Officers. It defines terms like vessel, underway, power-driven and sailing vessels. It outlines lighting requirements and sound signals. It discusses rules for determining risk of collision, taking action to avoid collision, operating in narrow channels, overtaking situations, head-on encounters, and crossing situations.
1) The document discusses celestial navigation techniques, including methods for determining speed, direction, and position using various historical instruments.
2) Key instruments mentioned include the sandglass, log, compass, lead, astrolabe, cross-staff, back-staff, quadrant, octant, chronometer and sextant.
3) The document also covers the three coordinate systems used in celestial navigation: terrestrial, celestial, and horizon. It provides examples of how sights are reduced using the Nautical Almanac and tables to determine position.
This document provides an overview of various navigation systems used in aviation, including Non-Directional Beacon (NDB), Automatic Direction Finder (ADF), VHF Omni-directional Range (VOR), Distance Measuring Equipment (DME), Instrument Landing System (ILS), marker beacons, radar, Global Positioning System (GPS), and approach lighting. It describes what each system is, how it functions, and its purpose in aiding pilot navigation.
Navigation aids such as lighthouses, beacon lights, buoys, and lightships are necessary to safely guide vessels through rivers, channels, harbors, and coastal waters. These aids help vessels avoid dangerous zones, follow proper harbor approaches, and locate ports during nighttime and bad weather. There are two main types of navigation aids: fixed aids like lighthouses and beacon lights, and floating aids such as buoys and lightships. Lighthouses are tall tower structures that can be seen from long distances, while beacon lights help identify directions and alignments. Buoys come in different shapes and types to demarcate channels and entrances. Lightships are small ships that act as lighthouses
The celestial sphere is a hypothetical sphere of infinite radius, concentric with the Earth, on which all stars and other celestial objects appear to be projected. It allows mapping the positions of stars, planets, and other celestial objects as they appear in the sky and provides a framework for spherical astronomy. The equinoctial system of coordinates divides the celestial sphere into an equatorial and an ecliptic plane using the celestial equator and the ecliptic.
The Sky
Astronomy is about us. As we learn about astronomy, we learn about ourselves. We search for an answer to the question “What are we?” The quick answer is that we are thinking creatures living on a planet that circles a star we call the sun. In this chapter, we begin trying to understand that answer. What does it mean to live on a planet?
The preceding chapter gave us a quick overview of the universe, and chapters later in the book will discuss the details. This chapter and the next help us understand what the universe looks like seen from the surface of our spinning planet.
But appearances are deceiving. We will see in Chapter 4 how difficult it has been for humanity to understand what we see in the #sky every day. In fact, we will discover that modern science was born when people tried to understand the appearance of the sky.
The document defines several key terms used in horizon systems of coordinates in astronomy:
- The horizon is a plane perpendicular to gravity through the observer's position, intercepting the celestial sphere.
- The visible horizon is the apparent horizon projected outward to intersect the celestial sphere.
- The astronomical horizon is the great circle formed by the intersection of the celestial sphere and a plane perpendicular to the line from the observer to the zenith.
- The zenith is the direction pointing directly above the observer, and the nadir is the direction pointing directly below.
The document provides details about the grounding of the passenger ship Royal Majesty in 1995 off Nantucket Island, Massachusetts. It describes how the ship was sailing 17 nautical miles off course after the GPS system had reverted to dead reckoning mode unnoticed by the officers. Upon arrival near Nantucket, the ship passed navigation buoys incorrectly and was sailing in incorrect depths. The ship ultimately grounded on Rose and Crown Shoal with 1,509 people on board. An investigation found the grounding was caused by over-reliance on automated systems, lack of training, deficiencies in the integrated bridge system, and failure of the second officer to take corrective action when cues indicated the ship was off course. Contributing
This document discusses the origins and definitions of various units of time measurement. It provides the following key points:
- Years, days, and months are based on the motions of the Earth, sun, and moon. A day is one rotation of the Earth, a year is one revolution around the sun, and a month was originally one revolution of the moon.
- Solar days vary slightly in length due to the elliptical orbits of planets and Earth's axial tilt. Local mean time uses longitude to account for time differences between locations.
- Astronomy uses precise time measurements like Greenwich Hour Angle and Local Hour Angle to determine positions of celestial bodies based on their movement relative to meridians. The Local Hour Angle
1. The document outlines the roles and responsibilities of the bridge watchkeeping team, including conducting regular checks of navigational equipment, compliance with collision regulations, and navigation procedures in different conditions.
2. It describes the roles of the Master, Officer of the Watch, helmsman, lookout, and pilot in ensuring safe navigation and navigation in compliance with international regulations.
3. Effective communication and coordination between all bridge team members is essential for safe navigation.
The United States Merchant Marine plays an important role in both peacetime trade and wartime support of military forces by transporting goods and materials overseas. However, the Merchant Marine has declined since World War II due to factors such as high costs and foreign subsidies undercutting U.S. ships. Maintaining a strong Merchant Marine remains vital for both economic and military security.
Longitude lines run vertically and converge at the poles, with 0 degrees located at Greenwich, England. Longitude ranges from 0-180 degrees east and west. Latitude lines run horizontally and are parallel, ranging from 0-90 degrees north and south of the equator. Significant lines of latitude can be associated with different body parts, with the North Pole as the head and South Pole as the toes.
Latitude lines run horizontally around the Earth and are parallel lines of equal distance. Longitude lines run vertically and converge at the poles. Together, latitude and longitude can precisely locate any position on Earth within the grid system of degrees, minutes, and seconds.
This document provides information about how to read maps and globes. It discusses scale, different types of scales like ratio and bar scales, and using latitude and longitude to locate points. It explains that latitude lines run horizontally and longitude lines run vertically. The prime meridian and equator divide the globe into hemispheres and quadrants. Topographic maps use contour lines to indicate elevation and slope steepness. Satellite imagery and GPS are now used to create digital maps.
Prime Meridian,Equator, Latitude and longitude Jamal Jamali
This document defines and explains key concepts related to latitude, longitude, and their use in determining locations on Earth. It discusses the prime meridian, equator, latitude, longitude, north and south latitudes, east and west longitudes, and the international date line. Latitude lines run parallel around the globe, measuring angles north and south of the equator, while longitude lines converge at the poles, measuring angles east and west of the prime meridian. Together, latitude and longitude precisely locate positions worldwide.
This document discusses key concepts relating to latitude, longitude, and time zones on Earth. It explains that the equator divides the planet into northern and southern hemispheres. Parallels of latitude run parallel to the equator and are measured in degrees from 0 at the equator to 90 at the poles. Important parallels include the Tropic of Cancer, Tropic of Capricorn, and Arctic Circle. The planet is also divided into torrid, temperate, and frigid zones based on sunlight. Longitudes are measured in degrees east and west from the Prime Meridian at Greenwich, England. Time zones are based on longitude, with each zone being approximately 15 degrees and 1 hour apart. Standard time is used within countries
_L-14 The Globe- Latitudes and Longitudes new.pptxpadminijyothi
Here are the answers:
1. The local time of a place situated 60° W of London will be 6 pm if it is noon in London. Since each 15° of longitude represents a 1 hour time difference, and the place is 60° west of London, the time difference will be 60/15 = 4 hours. So if it is noon in London, the local time at the place 60° W will be noon + 4 hours = 6 pm.
2. The local time of a place situated 90° E of London will be 3 pm if it is 9 am in London. Since each 15° of longitude represents a 1 hour time difference, and the place is 90° east of London, the time difference will be
This document discusses key geographic concepts including latitude, longitude, hemispheres, and time zones. It explains that latitude lines run east-west and measure degrees north and south of the equator, dividing the earth into northern and southern hemispheres. Longitude lines begin at the prime meridian and are numbered east and west. By using latitude and longitude coordinates, any location on earth can be precisely pinpointed. It also describes how the earth's rotation causes different time zones around the globe that are approximately 15 degrees apart.
Latitude lines run east-west and measure locations as degrees north or south of the equator, splitting the Earth into northern and southern hemispheres. Longitude lines begin at the Prime Meridian and measure degrees east or west, splitting the Earth into western and eastern hemispheres. Together, latitude and longitude coordinates provide a specific position anywhere on Earth.
Latitude lines run east-west and measure locations as degrees north or south of the equator, splitting the Earth into northern and southern hemispheres. Longitude lines begin at the Prime Meridian and measure degrees east or west, splitting the Earth into western and eastern hemispheres. Together, latitude and longitude coordinates provide a specific position anywhere on Earth.
The document discusses key concepts about determining locations on Earth using latitude and longitude.
Latitude is measured in degrees north and south of the equator, which divides the Earth into the Northern and Southern Hemispheres. Longitude is measured in degrees east and west of the Prime Meridian passing through Greenwich, England. Together, lines of latitude and longitude can be used to precisely identify any location on Earth.
The document provides information about latitude and longitude, including:
- Latitudes run horizontally around the Earth and are measured in degrees north and south of the equator.
- Longitudes run vertically and are measured in degrees east and west of the prime meridian in Greenwich, England.
- The location of any place on Earth can be identified using its latitude and longitude coordinates.
The document discusses key concepts related to maps and Earth's coordinate system, including latitude and longitude, prime meridian, International Date Line, and time zones. It explains that latitude measures the distance north and south of the equator in degrees, while longitude measures the distance east and west of the prime meridian. The prime meridian passes through Greenwich, England, and the International Date Line is the transition line for calendar days when traveling west or east.
1) Lines of latitude and longitude allow us to accurately describe locations on Earth. Lines of latitude run east-west and indicate how far north or south a place is from the equator, while lines of longitude run north-south and indicate how far east or west a place is from the prime meridian.
2) The prime meridian passes through Greenwich, England and is defined as 0° longitude. Longitude lines are numbered up to 180° east and west of the prime meridian.
3) To write the latitude and longitude coordinates of a location, write the latitude value first, followed by the longitude value. For example, the coordinates of Madrid are 40° 26' N 3° 42' W.
The document discusses key concepts related to globes and maps. It explains that a globe is a miniature model of the Earth that can be rotated to accurately show the sizes and positions of continents, oceans, and other geographic features. Parallels of latitude and meridians of longitude form a grid system on a globe, with the equator dividing it into northern and southern hemispheres. The Prime Meridian passes through Greenwich, England and longitude is measured in degrees east and west from there. The document also discusses time zones and how local times differ depending on a place's longitude.
Locations on Earth are described by their latitude and longitude coordinates. Latitude is the distance north or south of the equator, measured in degrees from 0 degrees at the equator to 90 degrees at the poles. Lines connecting points of equal latitude are called parallels. Longitude is the distance east or west of the Prime Meridian, measured in degrees from 0 degrees at the Prime Meridian to 180 degrees east and west. The Prime Meridian passes through the Greenwich Observatory in England. The rotation of the Earth causes the sun to traverse 15 degrees of longitude per hour, causing time to change by 4 minutes when moving between meridians. The International Date Line approximates the 180th meridian, where the date changes when traveling east or
This document provides information about latitude, longitude, and the coordinate system used to locate positions on Earth. It defines key terms like latitude, longitude, meridians, parallels, and the differences between them. Methods for calculating distances between points and angles subtended at the center of Earth are presented. Worked examples demonstrate how to find latitudes/longitudes of points, distances along meridians/parallels, and the shortest distance between two points on a great circle.
1) The document is a permission form for a Bishop Kenny High School student to participate in a junior varsity baseball tournament in Georgia from April 5-6, 2013.
2) It provides details on the student, destination, dates, required items, and dress code. It also includes a medical release and liability waiver.
3) Parents must sign giving permission for their child to participate in the overnight trip and authorizing emergency medical treatment, while also releasing the school from any liability in case of injury or accident during the activity or transportation.
The document provides an itinerary for a trip by Bishop Kenny NJROTC to compete in a Brain Brawl competition in Augusta, Georgia on April 5-6, 2013. The itinerary details the schedule including departure from and return to Bishop Kenny High School, accommodations at a hotel, times for meals, competition preparation and the competition itself at Cross Creek High School. Contact information for chaperones is provided at the end.
This three day NJROTC trip itinerary includes visits to the University of South Florida, MacDill Air Force Base, Tampa Aquarium, and Busch Gardens from April 26-28. Students will need money for meals and expenses. The schedule provides details of activities, transportation, meals, dress code, and curfews each day. Permission forms include contact information and expectations that students will represent their school appropriately.
The document is a permission form for a student to participate in an NJROTC orientation trip from April 26-28, 2013 to Tampa, Florida with LtCol Seckinger/MCPO Harris. It requires parental consent, a medical release, and a liability waiver. It details the student and parent names, dates and location of the trip, transportation by charter bus, required items, and contact information. It releases the school and chaperones from any liability while the student participates in the trip and transportation. The parent must sign by April 15th for the student to attend.
The document summarizes key concepts in the international law of the sea that have developed over centuries. It discusses concepts such as territorial seas, exclusive economic zones, continental shelves, the high seas, and international straits. It also outlines some principles established by Hugo Grotius regarding freedom of the seas. The document analyzes how international law of the sea developments could impact US Navy missions by potentially limiting mobility, increasing vulnerability to surveillance and interdiction, and imposing limitations on intelligence activities.
The document discusses the history and role of the U.S. Merchant Marine. It touches on key periods of growth and decline, important acts of Congress, ship types, and the Merchant Marine's contributions to national defense such as strategic sealift during wartime. The Merchant Marine is responsible for heavy lift tasks in support of overseas forces during wartime and transports the vast majority of global trade via ships registered in the U.S. and other nations.
The document discusses key concepts and terms in international law of the sea, including:
1) Territorial seas generally extend 12 miles from a country's coastline, with some countries claiming more extensive economic zones.
2) Beyond territorial seas are the high seas, which are open for use by all countries under the principle of freedom of the seas.
3) International law aims to balance countries' sovereignty over coastal waters with the rights of foreign vessels to pass through territorial seas and conduct activities in exclusive economic zones.
This document contains 31 multiple choice questions about navigation concepts and terms. It covers topics like units used on nautical charts, celestial navigation, electronic navigation aids like GPS and radar, methods for determining a ship's position, and concepts like dead reckoning. The questions are meant to test knowledge of fundamental navigation topics and terminology.
This document contains questions about navigation concepts including:
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- The significance of great circles in navigation
- Units of measurement like degrees, minutes of arc, and nautical miles
- Compass directions and true versus magnetic north
- Navigational instruments like the compass
- Features displayed on nautical charts like depth soundings and buoys
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This document is a field manual for the Navy Junior Reserve Officers' Training Corps (NJROTC) that provides information on uniforms, ranks, customs, inspections, and physical fitness requirements. It establishes guidelines for uniform wear and composition. It also outlines NJROTC and US Navy ranks and rates. The manual describes military customs, courtesies, etiquette, ceremonies and reviews. It provides instructions for personnel inspections and requirements to earn the NJROTC Physical Fitness Ribbon. The core values of NJROTC - Honor, Courage, and Commitment - are also defined.
This document provides regulations for the Navy Junior Reserve Officers' Training Corps (NJROTC) uniform. It outlines standards for personal appearance, uniform composition and wear for male and female cadets. Specific uniforms are described, including the Navy Service uniform, Service Dress Blue uniform and Working Khaki uniform. Regulations cover hair, grooming, insignia, awards and the proper wearing of the uniform. The purpose is to maintain a military image and uphold the dignity of the Navy through adherence to uniform standards.
The document provides an overview of international and inland nautical rules of the road. It discusses key topics such as required navigation lights for vessels, sound signals, and right-of-way rules for different vessel encounter situations such as meeting, overtaking, and crossing. Specific lights, shapes, and whistle signals that vessels must use to identify themselves and communicate intentions are described.
The document contains questions about nautical rules of the road, including:
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3) Vessel lighting requirements and the colors of running lights.
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The document discusses various topics related to time and navigation, including:
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- Radio stations located in the US and Hawaii broadcast time signals every five minutes to help mariners maintain accurate time at sea.
- The ship's clock is set by the person assigned to maintain accurate time aboard for log entries and messages.
- The military uses a 24-hour clock for consistency.
- Coordinated Universal Time (UTC) is the standard for atomic clocks worldwide and is also known as Greenwich Mean Time (GMT).
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2. Key aids to navigation include lights with specific flash patterns, colored buoys, dayshapes, and structures along channels and waterways.
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Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
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10. N pole Greenwich
England
W E
LONGITUDE
EQUATOR
S pole
Meridians and the equator are called
great circles because they divide the
globe into two halves.
11. Great Circle
Any circle formed by the intersection
of a plane passing through the Earth’s
center, with the Earth’s surface
12. Prime
Meridian
Parallels
Equator
The equator is the only great circle
going around the globe from east to
west. The other lines are called parallels,
since they go around the globe parallel
to, and north and south of the equator.
13. Greenwich meridian
(longitude 0°)
N
Equator
(latitude 0°)
One example
of a great circle S
A great circle is any circle whose
plane passes through the Earth’s
center, no matter what direction.
14. What is the significance of the
great circle in navigation?
15. What is the significance of the
great circle in navigation?
The shortest distance between
two points on the Earth lies along
the path of a great circle passing
through those two points.
19. 360° 360°
Greenwich meridian
N
Center of (longitude 0°)
The Earth Regardless of the
size of the circle,
the circumference
Equator
(latitude 0°) has 360°.
One example
of a great circle S
25. International
Date Line
New Date
Noon
Old Date
Old Day 0° Prime
Meridian
New Day
Midnight 180°
International
Date Line
International Date Line
26. Eastern
Hemisphere
International
Date Line
Equator
Pacific
Ocean
Western Hemisphere
27. Prime
Meridian
0° Longitude
Meridians
Meridians (longitude lines) between the
prime meridian and 180th meridian are
numbered 0° to 180° east (E) or west (W).
35. Remember!
North
Pole North
Latitude
South
Latitude
West East
Longitude South Longitude
Pole
• Longitude is always measured east
or west from 0° through 180°
• Latitude is always measured north
or south from 0° through 90°
53. On the compass rose above, only north
is filled in. Fill in the rest of the points
on the compass, going clockwise, using
the standard abbreviations.
54. On the compass rose above, only north
is filled in. Fill in the rest of the points
on the compass, going clockwise, using
the standard abbreviations.
56. Heading – Direction the ship is facing
Course – Direction the ship is steered
through the water
57. MAGNETIC COMPASS GYROCOMPASS
Magnetic compasses Gyrocompasses
give direction relative reference true
to magnetic north. north.
58. Gyrocompass
Navigational compass containing a
gyroscope, that, when adjusted for
latitude and speed, shows true north
or communicates this information
to one or more gyro repeaters.
63. How Variation Affects the Compass
Magnetic North North Pole
Variation
Remember, variation changes
depending on your position relative
to magnetic north.
64. Converting Direction
To convert from magnetic to true,
just add or subtract the variation
at your location to the magnetic
bearing.
Remember — Westerly variations
are subtracted, and easterly
variations are added.
65. Example of Converting Direction
If your ship was heading 080° magnetic
in a region where the variation was
10° East, what is the true heading?
66. Example of Converting Direction
If your ship was heading 080° magnetic
in a region where the variation was
10° East, the true heading would be
080° + 10°, or 090° true.
67. Example of Converting Direction
If your ship was heading 270° true in a
region where the variation was 10° East,
what is the magnetic heading?
68. Example of Converting Direction
If your ship was heading 270° true in a
region where the variation was 10° East,
the true heading would be 270° – 10°,
or 260° magnetic heading.
69. Bearing
The direction of an object from an
observer, measured clockwise in one
of three standard ways:
• True bearing
• Magnetic bearing
• Relative bearing
76. When recording a bearing, assume it to
be a true bearing unless followed by the
letters M or R.
030°M means 30° right of magnetic north
030°R means 30° off the starboard bow
77. Objects seen by lookouts are reported
in terms of relative bearing by degrees.
78. Relative Bearings
• Dead ahead, or bow – 000°R
• Starboard beam – 090°R
• Dead astern – 180°R
• Port beam – 270°R
79. To emphasize that it is a true bearing,
the letter T (for example 030°T) follows
the three-digit true bearing, spoken
―030 degrees true.‖
80. TN
RELATIVE
BEARING
030°
090°
TRUE Light
BEARING House
True Bearing = Relative Bearing + True Heading
(Subtract 360° if sum is greater than 360°)
83. Hydrography
Science of measurement, description,
and mapping of the Earth’s surface
waters, with special reference to their
use for navigation
84. Hydrographic information
given on a chart includes:
• Water depths
• Nature of bottom
• Overhead obstructions
• Navigation aids; buoys,
lights, and anchorages
85. Globe Chart
Impossible to Necessary to
work navigation work navigation
problems or problems
chart courses
87. It is necessary
to convert the
round surface of
the globe to one
that is flat and
two-dimensional
(having only
length and
width)—to
a flat piece of
paper on which a
chart is drawn.
91. Mercator Projection
Earth is projected onto a
cylinder-shaped piece of paper,
wrapped around the globe at the
equator
92. Geradus Mercator
Mercator Projection
• Commonly used for navigational charts
• Developed by a Dutch cartographer,
Geradus Mercator, in the 1500s
• Most useful projection for navigation
93. Great Circle
Track
Rhumb Line
Conformal Projection
A projection on which any rhumb line is shown
as a straight line, used chiefly in navigation,
though the scale varies with latitude and aerial
size and the shape of large areas are greatly
distorted
94. Rhumb Line
A curve on the surface of a sphere
that cuts all meridians at the same
angle; the path taken by a vessel or
aircraft that maintains a constant
compass direction
95. Scale of Charts
SCALE 1:7,500,000
• Used to measure distance
• Relationship between actual
and chart distance
• Printed near the legend as
a ratio, such as 1:7,500,000
96. Small scales
are used to
depict large
areas on a
chart, and
large scales
are used to
depict small
areas.
97. Measuring distance on a chart
If an inch on the chart represents 50 miles,
what would five inches represent?
98. Measuring distance on a chart
If an inch on the chart represents 50 miles,
what would five inches represent?
250 Miles
99. Remember
• The larger the scale, the smaller the
area shown on a given chart or map.
• The large-scale charts show areas
in great detail.
• Features appearing on a large-scale
chart may not show up at all on a
small-scale chart of the same area.
101. Nautical charts have information for
safe navigation, such as:
• Symbols, figures, and abbreviations
• Depth of water
• Type of bottom
• Navigational aids
102. Harbor charts are large-scale charts that
show harbors and their approaches in
detail.
111. Plotting
In order to use the nautical chart for
navigating, you must know something
about how courses, bearings, and
lines of position are plotted on it.
113. Parallel Rulers
A pair of straightedges connected by
two pivoted crosspieces of equal
length so as to be parallel at all times;
used for various navigational
purposes, especially for transferring
the bearing of a plotted course to a
compass rose
117. Fix (position)
Accurate position determined without
use of any previous position, using
visual, electronic, or celestial
observation
118. Line of Position
(LOP)
A line indicating
a series of possible
positions of a ship
as a result of
observation or
measurement
119. SPIRE
RANGE BEARING
Lines of Position
CAPE
DISTANCE ARC
TANGENT
120. Bearing Lines of Position
Lines corresponding to the bearings
are plotted on the chart. They are
labeled with the 4-digit time of
observation above the line.
124. Radar Stadimeter
Devices used to
measure distance
to a landmark
Sextant
125. Stadimeter
Optical distance-measuring device
that measures angles to determine
distance to an object using as a
reference the distance to an object of
known height
127. Sextant
An astronomical instrument used to
determine latitude and longitude at
sea by measuring angular distances,
especially the altitudes of Sun, Moon,
and stars
129. Obtain a fix with these combinations
of lines of position:
• Two or more lines of bearing
• A distance arc and a line of bearing
• Two or more distance arcs
• A visual range and a distance arc
• A visual range and a line of bearing
• Two simultaneous visual ranges
Most commonly used
142. Sound Ranging
A method for determining the distance
between a point and the position of a
sound source by measuring the time
lapse between the origin of the sound
and its arrival at the point
SONAR (S0und NAvigation
and Ranging)
143. In piloting, soundings are usually
taken every 5 minutes.
D=1/2 t x 4,800 feet per second
144. A fathometer may
establish a fix
when a navigator
has a chart
showing accurate
bottom contours,
but in practice it
usually serves as
a check.
155. The most common scope used is a plan
position indicator (PPI), which gives a
bird’s eye view of the radar coverage
area, the transmitting ship in the center.
156. Advantages of radar as a navigational
aid include:
• It can be used at night and during
periods of low visibility.
• A fix can be obtained from a
single object.
157. • Very accurate and rapid
• Used to locate and track storms
• Very important for ship safety
160. Loran is a system
of radio signals
broadcast by
stations of known
position.
161. Loran Receiver
A loran fix is determined by a loran
receiver from the intersection of lines
of position obtained from those shore
stations.
162. GPS Satellites
Satellite Navigation
The newest electronic navigation system
is the Global Positioning System (GPS).
163. Global Positioning
System (GPS) • Six 10,900-
mile-high
orbits
• 24 satellites
• Continuous
three-
dimensional
fix capability
• Fix accurate
to within
±10 meters
165. GPS is used for a wide variety of land
navigation purposes, including position
and direction-finding in many new cars
and golf carts.
166. Military applications of GPS navigation
systems include guidance for:
• Smart bombs
• Cruise missiles
167. Differential GPS
Enhancement by to basic GPS: corrections to
positioning information is determined by land-
based receivers and transmitted to users.
Capable of accuracy to within + 1 meter.
168. Ship’s Inertial Navigation
System (SINS)
Provides accurate and continuous
dead reckoning (DR) positions
169. SINS gives ships an accurate and
continuous dead reckoning position
using three gyroscopes to determine
latitude, vertical, and longitude with
great accuracy.
170. Submarines use SINS to navigate when
submerged for months even when
traveling under the Arctic ice cap.
171. Celestial
Sphere
Celestial Navigation
Branch of navigation in which position is
determined by the aid of heavenly bodies
such as the Sun, Moon, and selected stars
and planets
175. INDEX MIRROR
LENS
HORIZON
INDEX ARM HOOD
MIRROR
TELESCOPE
VERNIER
ARC SCALE
SCALE
MICROMETER
DRUM SCALE SCREW
Sextant — Nomenclature
Reading the Vernier Scale
176. Dead Reckoning
Calculation of one's position on the
basis of distance run on various
headings since the last precisely
observed position, with as accurate
allowance as possible being made for
wind, currents, compass errors
194. At sea, the navigator will use celestial or
electronic means to get positive fixes at
least every morning, noon, and evening.
195. In piloting waters, the navigator will
normally be on the bridge getting exact
fixes whenever usable navigation aids
come into sight.
196. Currently, electronic plotters incorporate
continuous fix updates received from
GPS, then project current ship’s position
and the DR track onto an electronic chart
projection on a computer screen.
242. Q.23. What is a fix?
A.23. An accurate position
determined without reference
to any previous position. The
intersection of 2 or more lines
of position.
243. Q.24. What is the difference between
directions measured on a
gyrocompass and those
measured on a magnetic
compass?
244. Q.24. What is the difference between
directions measured on a
gyrocompass and those
measured on a magnetic
compass?
A.24. Directions measured on a
gyrocompass are relative to
true north, whereas directions
measured on a magnetic
compass are relative to
magnetic north.
245. Q.25. How is distance on a Mercator
chart measured?
246. Q.25. How is distance on a Mercator
chart measured?
A.25. On a flat surface along any
meridian where one minute of
latitude equals one nautical
mile
247. Q.26. If a half-inch on a chart
represents 10 miles, how many
inches would represent 100
miles?
248. Q.26. If a half-inch on a chart
represents 10 miles, how many
inches would represent 100
miles?
A.26. Five inches
249. Q.27. What is the shortest distance
between two points on a
globe?
250. Q.27. What is the shortest distance
between two points on a
globe?
A.27. An arc of a great circle
254. Q.29. What is a line of position
(LOP)?
A.29. A line drawn on a chart along
which a ship must be located,
based on a bearing or distance
from an object or landmark
255. Q.30. A ship that is traveling south
observes another ship on a
relative bearing of 041 degrees.
What is the true bearing to that
ship?
256. Q.30. A ship that is traveling south
observes another ship on a
relative bearing of 041 degrees.
What is the true bearing to that
ship?
A.30. 221 degrees true
(180 degrees + 041 degrees)
257. Q.31. A ship that is traveling north
observes another ship on a
relative bearing of 041 degrees.
Where would you see that ship
in relation to your ship?
258. Q.31. A ship that is traveling north
observes another ship on a
relative bearing of 041 degrees.
Where would you see that ship
in relation to your ship?
A.31. Off the starboard bow
259. Sphere
A round body whose surface is at all
points equidistant from the center
260. Meridian
A great circle of the Earth passing
through the poles and any given
point on the Earth's surface
263. Compass Card
A circular card with magnets attached
to its underside, the face divided on its
rim into points of the compass, degrees
clockwise from north, or both, and
floating or suspended from a pivot so
as to rotate freely