Marine Electronics – Reviews VHF Marine Radios
Editor’s Note: This is the first in a series of articles that will cover what marine electronics should be considered for the boater looking to equip their vessel with the latest in technology.
Today there are myriad ways to communicate. Cell phones, texting, tweeting, Facebook, e-mails and a multitude of other ways to reach out to others have made communication instant and easy. But with all these choices, which is the best way to communicate when you are out on the boat and, in particular, in an emergency? Have you considered a VHF Marine Radios?
Many may say their cell phone is adequate, but the truth is that relying on your cell phone while on the water could prove to be not only ineffective, but dangerous. A hand-held or fixed-mount VHF Marine radios is a wise choice onboard. It may even be the most important piece of electronic equipment you buy for your boat.
There are many areas where a cell phone may have enough signal strength to get a call out. But there are also many areas where there is little or no signal. This can be true even in high traffic coastal areas. A VHF (Very High Frequency) marine radios that operates within the frequencies allotted for marine use can transmit a signal that can be received anywhere within its range. The U.S. Coast Guard monitors emergency bands of VHF marine radios transmission 24 hours a day, seven days a week along with other marine vessels, marinas and waterside facilities. The fact is, if you need to communicate on the water your best option the majority of the time is a VHF marine radios.
VHF marine radios are two-way radios that operate within a set of frequencies that have been allotted by the FCC and other international regulatory agencies to allow for marine and maritime communication. VHF marine radios commonly found on recreational vessels come either as fixed-mount devices or as hand-held portables. The former is designed to be installed onboard and wired into the vessel’s electrical system. It is comprised of the radio itself and a separate mounted antenna. It has the ability to transmit up to 25 watts, the maximum allowed by the FCC.
New fixed-mount VHF marine radios are required to have the ability to transmit an automatic mayday signal (known as DSC or Digital Selective Calling) that, when connected to an active GPS, will also transmit your position at the time the distress button is pushed. This could prove invaluable in a distress situation where time is short and information may not be broadcast verbally. To properly use this function, radios must be registered to obtain a unique MMSI (Maritime Mobile Service Identity) number. It is a simple and free process and can be done at boatus.com/mmsi. Once transmitted, this unique identifier is part of the mayday signal, and rescue authorities along with any other vessel monitoring DSC can identify the vessel in distress.
A fixed mount radio requires an external antenna. This antenna can come in a variety of lengths and is just as important a component as the radio itself. All VHF marine radios operate at line of sight, meaning that wherever the top of the antenna can “see” is where it can broadcast. One must also consider that many Coast Guard towers are tall and can increase the range as they view farther over the horizon. Sailboats, with mast-mounted antennas, generally have a longer range as well. A simple way to determine the effective range of your radio is to use this formula: square root of the height above the water in feet times 1.42 equals range in miles. The longer (higher) the antenna, the farther the range of transmission. Common lengths range from a 3-foot stainless whip antennas to 21 foot two- and three-piece fiberglass models.
Other factors that should be considered when selecting an antenna are what they are made of, how and where they will be mounted to the boat and their gain. Some VHF marine radios antennas may look similar but their internal components can make a huge difference in their performance. Lower priced economy antennas may be nothing more than a coaxial cable held in place with foam supports inside a fiberglass shaft. Better performing antennas will have single or multiple copper elements inside allowing for better transmission and reception of radio signals. Check the construction prior to purchasing. You could have the best radio on the market but pair it with a low-end antenna and performance will be less than expected.
The antenna mounting location and appropriate mount also need to be considered. Gain should be another deciding factor. The gain of the antenna in marine applications refers to the radiation pattern of the antenna. A three-foot stainless antenna has a 3 dB gain, meaning that it transmits a spherical or rounded pattern sending the signal in all directions. This is particularly good if it is mounted on a sailboat mast that is healed over, as the radiation is wider and not just transmitting to space or in the water. A taller, 21-foot antenna may transmit at a 9 dB gain, which is a narrower, more conical pattern that will transmit better over longer distances in calmer water from a boat that doesn’t rock or pitch too much. Most smaller vessels will have a 3 or 6 dB antenna for the best compromise.
Handheld VHF marine radios run on their own battery power (alkaline, nickel cadmium or lithium ion batteries), they are not dependant on shipboard power and are completely portable. They can be taken boat to boat and are often used as a backup to a fixed-mount VHF. Their effective range may be less than fixed-mount radios, but range can be increased slightly if the radio is used in a tower or a high point onboard. Their transmit power is regulated to be no higher than 6 watts by the FCC and can be adjusted in some models to transmit on 1 watt or 3 watts to conserve battery power.
Handhelds are a common option in smaller boats plying near- and inshore waters. Many new models such as those from Icom, Uniden, and Vertex Standard float and some even have emergency LED strobes and built in GPS units. Effective range for these radios is about five miles. While limited, that’s still better than a cell phone with no signal.
Whichever VHF marine radios you decide to go with, it is important that you have a radio that will give you the ability to communicate in an emergency, or even a non-emergency, to the appropriate people who can help while you are aboard your vessel. It may just be the most important piece of electronics you purchase. It can save lives and property and, if nothing else, make your days on the water more pleasurable.
Glenn Hayes is a regular contributor to All At Sea Southeast. Find him online at hayesstudios.com.