This document discusses tide calculation using U.S. tide tables. It explains that tide tables are published in 4 volumes by the National Ocean Service covering different regions of the world. Each volume contains 5 common tables providing tide height predictions for reference stations and information to modify these for other locations. The document also defines several tidal datums used in tide calculations like Mean Lower Low Water and Mean Sea Level. It includes two examples of calculations to find actual sea level or time based on charted depth, tide readings and tide information for a location.

1. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
TIDE CALCULATION
U.S TIDE TABLES

2. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel

3. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
Tide tables for various parts of the world are published in 4
volumes by the National Ocean Service. These volumes
are:
1. Europe & West Coast of Africa including Mediterranean
Sea.
2. East Coast of North & South America including Greenland.
3. West Coast of North & South America including Hawaian
Islands.
4. Central & Western Pacific and Indian Ocean.

4. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel

5. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
Each volume has 5 common tables:
• Table 1 contains a complete list of the predicted times and heights
of the tide for each day of the year at a number of places
designated as reference stations.
• Table 2 gives tidal differences and ratios which can be used to
modify the tidal information for the reference stations to make it
applicable to a relatively large number of subordinate stations.
• Table 3 provides information for finding the approximate height of
the tide at any time between high water and low water.
• Table 4 is a sunrise-sunset table at five-day intervals for various
latitudes from 76°N to 60°S (40°S in one volume).
• Table 5 provides an adjustment to convert the local mean time of
table 4 to zone or standard time. consecutive number to assist in
locating the entry in table 2.

6. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
TIDAL DATUMS
Mean Lower Low Water (MLLW) is the average height of the
lower low waters of each tidal day.
Mean Low Water (MLW) is the average height of all low waters at a
given place. About half of the low waters fall below it, and half
above.
Mean Sea Level (MSL) is the average height of the surface of the
sea for all stages of the tide over a 19 year period.
Mean High Water (MHW) is the average height of all high waters
over a 19 year period.
Mean Higher High Water (MHHW) is the average height of the
higher high waters of each tidal day.

7. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
MLLW (CD)
MLW
WATER LEVEL
MHW
CHARTED DEPTH
MSL
MHHW
SOUNDING
( DOW)
HEIGHT OF TIDE
H.O.T

8. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel

9. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
Find the actual sea level, if the C.D
is 25 ft. at 15:43 (LMT) on 5th.
January 2000.
1. Duration: HWT – LWT
16:21 – 10:01 = 6h:20m (Raising)
2. Range: H of HW – H of LW
17,3 – 5,3 = 12 ft.
3. Δt: Reference time the nearest
high water time or low water time.
Δt: HWT – DT : 16:21 – 15:43
Δt: 0h:38m Before HW

10. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
C.D
25
SEA BOTTOM
H of LW: 5,3
HW 16:21
Range:12
HOT
CTH
H of HW: 17,3
LW 10:01
15:43
W L
DOW = 25 + 17,3 - CTH

11. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
Actual range = 12
Δt = 0h:38m Before HW
Duration = 6h:20m
CTH : 0,3 ft.
Nearest to HW
DOW : 25 + 17,3 - 0,3 : 42 ft.

12. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
18th January 2000; The sounding
taken 40,2 ft. by hand lead line at
P.M falling time. If the C.D is 35 ft.
Find the exact time.
1. Duration: HWT – LWT
20:02 – 13:43 = 6h:19m (Falling)
2. Range: H of HW – H of LW
17,3 – 4,3 = 13 ft.
3. Δt: Reference time the nearest
high water time or low water time.

13. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
C.D
35
SEA BOTTOM
LW 20:02
H of LW: 4,3
HW 13:43
Range:13 P:MW L
HOT
CTH
H of HW: 17,3
40,2 = 35 + 4,3 + CTH; CTH: 0,9

14. DOKUZ EYLUL UNIVERSITY
SCHOOL OF MARITIME BUSINESS AND MANAGEMENT
DEPARTMENT OF DECK
E.Gürel
Actual range = 13
Δt = ?????????????????
Duration = 6h:19m
CTH: 0,9
Nearest to LW
DT : LWT – Δt
DT : 20h:02m – 01h:03m
DT : 18h:59m