Cruise 
Communications 
Marius Coomans
The Way We Were
Here and Now…
Marine Communication 
• Radio Communication 
• Antennas 
•Emergencies 
• Automatic Identification (AIS) 
• Satellite Phones
Online Communication 
• Internet Access 
• Managing Telstra 
• Position reporting with Skipr.net 
• Online Applications
The Radio
VHF v HF
Fixed and Mobile
Antennas
Antennas
Antennas
Antennas
Typical whip antenna 
radiation pattern 
The higher the gain, the narrower the beam
The effect of heel on transmission
Distance to Horizon 
Yacht A (10 m) - 11.3km (6 NM) 
Yacht B (20m) - 16 km (8.6 NM) 
Tower (100m) - 35.7 km (19.3 NM)
Repeaters (ch 20-22 , 80-82)
Antennas 
• Antennas are matched to a Frequency (band) 
• What matters is Power Delivered rather than 
transmitter power 
• VHF and higher bands operate on the basis of 
"line of sight“ 
• The gain and radiation pattern of an antenna 
are critical.
Emergency 
Communications
Mayday Call 
Mayday, Mayday, Mayday, this is Boatname, 
Boatname, Boatname. [break] 
Mayday, this is Boatname, we are taking on 
water and are about to abandon ship. 
Our position is: 
31 degrees, 23 decimal 45 minutes South, 
152 degrees, 15decimal 67 minutes East. 
We have two people on board.
Mayday?
Mayday?
AIS instruments
Satellite Phones 
• Inmarsat 
• Iridium 
• Globalstar
Inmarsat 
Geo Stationary Orbit
Iridium 
Low Earth Orbit
Globalstar 
Low Earth Orbit
Selecting a Satphone 
• Rent or Buy 
• Emergency or Routine Comms 
• Voice, Data and/or Text 
• Coverage 
• Price
Satellite Communications 
more than mere phones…
Online Communication 
• Mobile Internet 
• Position reporting with Skipr 
• Online Applications
+ Familiar, flexible, no commitment 
- Poor battery life, limited coverage 
+ Economical, flexible, multi-user 
- Another battery, another plan 
+ Best coverage, set & forget, always on 
- Requires installation, another plan
850 MHz v 2100 MHz 
Number of Phone Towers
Permanent Antenna
Internet in a Sock
Telstra Pre-paid Data
Telstra Pre-paid Data 2011
Telstra Pre-paid Data 2014
Gigabyte 2011 2014 
1 $40 -30 days $15 - 10 days 
4 $80 - 60 days $50 - 60 days 
10 $150 - 365 days $100 - 90 days 
12 $200 - 365 days 
Telstra Pre-paid Data
Skipr.net
Online Applications 
On the Internet, 
nobody knows you’re “away”.
Online Communication 
• Internet Access Alternatives 
• Managing Telstra 
• Position reporting with Skipr
Cruise Communication 
Links 
Credits, further reading: 
Rob’s Passage Planner – http://skipr.net/goodies/robs-passage-planner/ 
Skipr.net - http://skipr.net/ 
Telstra references – downloaded March 2011 - http://telstra.com.au/ 
VHF Marina Antenna Fundamentals - http://boat-project.com/tutorials/vhfant.htm 
Wikipedia on AIS - http://en.wikipedia.org/wiki/Automatic_Identification_System 
Iridium Go https://www.iridium.com/products/Iridium-GO.aspx?section=support 
Also see handout. 
Marius Coomans – skipper@skipr.net

Cruise communications 2014