134 Chapter Three
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• Have transmitter power up to 25 watts.
• Use external antennas that are long
and located high on the boat.
• Have the longer range because of the
latter two factors (Figure 12-2).
• Handheld VHF radios:
• Are limited to a maximum power of 6
watts (most offer a maximum of 3 to
5 watts).
• Are normally battery powered, which
limits available transmit power.
• Have a small antenna due to the
nature of their design.
• The antenna is on the unit, so it is
lower in the boat.
• Have an effective range of about 3
miles but typically not more than 8
miles because of the latter two factors.
However, they are a good backup to a
fixed-mount radio and good to have
if you need to abandon your vessel.
Licensing Requirements
You do not need a license to operate a VHF
radio, radar, or EPIRB (Emergency Position
Indicating Radio Beacon) on your
recre ational boat in U.S. waters.
A ship’s station license issued by the
Fed eral Communications Commission
(FCC) is required if you:
• Operate a boat over 65.6 feet (20 meters)
long.
• Travel to foreign ports or talk to for eign
stations.
• Use a single side-band (SSB) radio or
International Maritime Satellite Organization
(INMARSAT) equipment.
A restricted radiotelephone operator’s permit
may also be necessary if you visit a foreign
country. If you are required to have a
license, it must be on board and available
for inspection whenever you are underway.
See Appendix A.
Figure 12-1. Fixed (above) and
handheld (right) VHF radios
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36ft 24ft 12ft 6ft Antenna Height 18 ft 30 ft 300 ft
Figure 12-2. VHF radio range
Distance to Horizon
3.0 nm
add distances for both antennas
5.1 nm
6.6 nm
4.2 nm
5.9 nm
7.3 nm
Radio Horizon
no coverage for antennas
below the radio horizon
21 nm