VHF Radios: Why You Need One
In this age of e-mail, fax machines, pagers, and cell phones, there
is no shortage of ways to get your message across. But when you're out
on the water, what's the best device to maintain your lifeline to shore?
Today's boaters are faced with many choices for ship-to-ship and ship-to-shore
communications. VHFs, cell phones, Family Radio Service radios, CB radios,
Single Sidebands, and satellite communications are among the myriad
of choices available.
VHF
Radios
VHF (Very High Frequency) radios are the two-way radios most commonly
used by pleasure boaters and commercial ships in coastal and inland
waters. They are essential for emergency situations, and are monitored
24 hours a day by the Coast Guard.
Fixed-Mount
VHF Radios
VHF radios are available in both fixed-mount and hand-held models. All
fixed-mount VHFs have a maximum output of 25 watts, the maximum allowed
by the FCC. VHF is a line-of-sight system, which means the radio waves
won't bend to follow the curvature of the earth. The VHF antenna must
"see" the antenna of a distant station. Therefore, antenna height is
more important in determining range than radio wattage. The effective
useful range of a VHF radio is 20-25 miles.
Hand-Held
VHF Radios
VHF handhelds also offer many of the same features found on fixed-mount
units. They offer portability in the same way a cordless phone allows
more mobility at home. A handheld radio may be just what you need for
use in a dinghy, small boat without electrical systems, or as an emergency
backup for your boat's radio. Handhelds have a maximum output of six
watts. Due to their short antennas, they have a limited range of five
miles.
A significant increase in range can be achieved by connecting an external
antenna or using a telescoping antenna mounted to the hand-held radio.
Battery life varies with the size of the battery pack. Many models have
optional battery packs with longer operating times, or greater transmitting
power, or both. Some have battery saver circuits that turn off the receiver
to save power. The battery life of a handheld can be increased by switching
from full transmit power to one watt of transmit power. Handhelds are
not DSC capable.
Necessary
VHF Channels
The most important channel on a VHF radio is Channel 16, the international
distress and calling frequency. Channel 9 is used for hailing, radio
checks, plus some other functions. In Florida, for example, 9 is the
bridge tender's channel. Channel 6 is for ship-to-ship safety calls
after contact is made on another frequency. Channel 13 is for boat-to-boat
navigation. Channel 22 is for emergency transmissions once directed
by the Coast Guard to switch from another channel. Channels 24-28 and
84-88 are where you'll find a marine operator available to connect you
to a land-based line. WX-1-3 are the NOAA weather channels.
DSC
Capability
Digital Selective Calling, or DSC, is the equivalent of a "mayday button"
on a VHF or SSB. When activated, it automatically broadcasts an encoded
distress call that will be picked up by all nearby vessels equipped
with DSC. If the radio is interfaced with a Loran or GPS, it will also
automatically broadcast the distressed vessel's position. A few high-end
radios now include it as a feature, so when it becomes fully operational,
your VHF will be able to take advantage of this latest feature. To use
DSC, you must obtain a MMSI (Maritime Mobile Service Identity) number.
You may do so free of charge at this web address: (click on link or
copy and paste into your web browser). http://www.boatus.com/mmsi.
Keep in mind that the U.S. Coast Guard is not yet responding to DSC
transmissions. Currently, monitoring is scheduled to begin in 2007.
Cellular
Telephones
Having a cell phone on board allows you to keep in touch with land-based
people and businesses easily. They are very convenient and should be
used in tandem with a VHF. Cell phones, although very convenient on
land, are less reliable on the water. Most are not water resistant,
and their range is relatively short. The maximum range to and from a
cell antenna/station varies, but it is basically line-of-sight. Range
is further complicated by the fact that the majority of cell antenna/stations
are placed with land-based use in mind, so the distance offshore that
a vessel can remain in contact is frequently short. Cell phones can
also be expensive to operate, although there are many different packages
available. Your communication power with a cell phone is limited on
the water because the other ship you are trying to contact must also
have a cell phone. In some areas, you can place a call to the local
Coast Guard station by dialing *CG.
Family
Radio Service Radios
Family Radio Service radios are intended for personal, non-commercial
use like CB radios. They are very handy because they can be used on
land for communication without a license. They are perfect for outdoor
trips with friends and family where you need to stay in contact. And
they also help with communications while still on the boat. You can
talk to each other from bow to stern, from below to above deck, and
more! The range is typically 1-2 miles and is line-of-sight like VHFs
and cell phones. They have limited battery power and no emergency channel.
They operate in the 460mHz UHF band between VHF radios and cell phones
and transmit at 0.5 watts. Because these units have become so popular,
you may want to pre-arrange what channel you will be using and test
it out-very often one or more channels will be overloaded, especially
in crowded areas.
CB
Radios
Citizen band radio is intended to afford the general public economical
access to two-way radio communication. CB is allocated 40 specific frequencies
between 26.965 and 27.405 mHz, commonly referred to as channels 1-40.
Any channel may be used with either single or double sideband amplitude
modulation except Channel 9, which is reserved for emergency communications.
CB stations are limited to 4-watt carrier waves output power on DSB
AM, and 12-watts PEP on SSB AM. The usual reliable range of CB is five
miles. There are several pitfalls to having a CB radio on the water:
Making contact may be difficult, since not all boats have CB radios.
Channel noise and station traffic are sometimes heavy, and the Coast
Guard doesn't monitor the emergency channel.
SSBs
Single sidebands operate in the medium frequency (MF) and/or high-frequency
(HF) bands for reliable direct-voice communications over distances exceeding
25 miles (depending on antenna heights). SSBs are commonly available
with an output power from 50-150 watts. An SSB's range is affected by
the strength of the radiated signal, among other things. The maximum
reliable range in the 2-3mHz (MF) band during the day is 50-150 miles.
Transmission in HF band can reach thousands of miles.
Unlike VHF radios, SSBs require a large ground plane in order to radiate
its signal which except on metal hulls, needs to be installed in the
form of a large copper mesh panel (sometimes built onto the fiberglass
hull). With SSBs, antenna selection and installation is also more complicated.
SSBs generally require a much longer antenna than VHFs, and different
antenna tuning for different bands.
Satellite
Communications
Iridium is the first example of a worldwide voice communication system
which can be accessed using a small hand-held telephone. The 66 iridium
satellites have the ability to forward voice phone calls from one another
and then relay the conversations to ground stations. Magellan's GSC
100 Personal Satellite Communicator is for those who need worldwide
e-mail capabilities. Using 36 ORBCOMM satellites, the constellation
allows real-time data communications with low per message costs and
low hardware costs.
Our
Recommendation
For reliable on-the-water communications, we recommend using either
hand-held or fixed-mount VHF radios. When you're stuck in a jam-whether
from engine failure or a fierce storm approaching, a VHF radio can be
your lifeline to the world. In Coast Guard jurisdictions, VHFs are monitored
24 hours a day, seven days a week. For extra assurance, the USCG and
most TowBoatU.S. towers can locate your boat by tracking your VHF signal.
VHFs are handy in an emergency, but they have other uses: telephone
calls to shore, obtaining supplies and services such as marina reservations,
and boat operations like drawbridge openings and communicating with
commercial and other recreational vessels. The Federal Communications
Commission (FCC) regulates marine radio traffic and dictates that all
other uses are secondary to safety, so chatting is frowned upon by the
FCC and forbidden on Channel 16 and 9.
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