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Chapter 14: Nautical Radio Gear and Procedures and Your First Longer Cruise 197
Boat Bytes
The factors that most affect VHF transmission are the “gain,” or amplifying ability
of the antenna, and its height. A 6-dB gain model or higher is needed for good
range (provided the antenna remains approximately vertical). And an antenna
atop a flying bridge or on a sailboat mast can reach out miles farther than one
on a center console. However, for best performance from a sailboat at a high
angle of heel, a lower gain antenna is preferable, because it doesn’t concentrate the
signal into such a narrow horizontal disc.
Most people monitor a single channel, channel 16, so any time you need to make contact,
you can simply broadcast a hailing call and all nearby boats will hear it. The Coast Guard
and many marinas also monitor channel 16, so that’s where you go if you ever need to
broadcast the dreaded MAYDAY call. (Channel 9 is also used as a hailing channel, but it’s
not monitored by the Coast Guard.)
Channel 16 was the hailing channel for many years, and most boaters still use it that way,
but it is now supposed to be used only for emergency hailing. Channel 9 is now the hailing
channel for recreational boating. Use it for initial contact, and then jump to a “working”
channel, typically 68, 69, 71, 72, and 78. For details, visit http://wireless.fcc.gov/
marine/vhfchanl.html.
VHF radios cost $160 to $300. It’s a good idea to buy waterproof models for small, open
boats. The system requires an antenna about six to eight feet long for good performance,
another $75 to $100 or more.
Even with a good antenna properly mounted,
the range is limited to about 25 miles max. But
along the coasts of the United States, it’s rare to
be more than 25 miles from another VHFequipped
boat these days, so you can usually
reach someone when you need to.
VHF radios are small—about half the size of a fax
machine—and fit easily inside even the smaller
consoles on open boats. They’re built to withstand
the rigors of life afloat. Some are completely
sealed and will operate totally submerged.
(Unfortunately, you won’t—so call for help early if
you have problems.)
Boat Bytes
On small fishing boats, the
tall antenna of a VHF gets
in the way of the backcast.
On these rigs, it’s better to
opt for a low-profile “whip”
style antenna that’s only three
feet long, yet rated for 6 dB. It
won’t match a full-size antenna
over a long reach, but it’s adequate
most of the time and a lot
less likely to snag your lures.