In simple terms, a VHF marine radio is an essential communication device that helps with your safety while at sea. You can choose a marine radio with talking range of 5 to 50 miles and the fastest access possible to rescue agencies and the Coast Guard. A marine radio is helpful for chatting with lock/bridge operators, checking weather news, and communicating with other boats.
Marine VHF radios use radio waves for receiving and sending transmissions. The line of sight is an important part of their functioning. If the line of sight is blocked by things like earth curvature, land mass etc the signals will be disrupted. Thankfully, most of these obstacles are absent when you are on the open sea. The power of a marine VHF radio depends on the length of its antenna and wattage. For instance, if several boats are transmitting simultaneously on a single frequency, the strongest signal comes through.
Handheld or fixed mount
You will generally find two types of VHF marine radios – one that is handheld and the other with a fixed mount. A fixed mount gives you the maximum range possible and can draw power from the boat’s electrical system. Therefore, your batteries would be needed, unlike the handheld systems. However, in emergencies, you may need a handheld system and it is always desirable to have both if you can afford.
Generally, no license is required for operating marine radios except for commercial vessels. However, it is always helpful to reconfirm your local regulations in this regard.
We now turn to some of the important attributes of a marine VHF radio to help you with the shopping.
A line of sight:
As mentioned earlier, the line of height is crucial for effective communication, particularly during emergencies. With an antenna that is one foot above the sea level, your communication range is about 5 miles to another boat that has an antenna 20 feet above the sea level. If the antenna of the other boat is 100 feet asl, the range is about 12 miles and you can reach most coast guard stations with ease.
VHF marine radios are often lifesavers. Therefore, when you are shopping for one, look for ‘waterproof’ products and stay clear from ‘water resistant’ offerings. Waterproof devices with IPX7 GPS rating are ideal for most deployments.
Marine devices that are not designed for floating are good enough as long as you are on board. Waterproof helps if you dropping the device in shallow waters. A floating unit is your best choice, tough floating cases and collars can work on some occasions.
You should be able to see the display with sunlight. The display size, backlight intensity and anti-reflective screen are the properties you should look for. Glare or reflection can come from 3 surfaces i.e. the two sides of the screen and the LCD panel surface. The best way to verify this factor is to get the VHF radio powered and walking outside the shop to examine daylight viewing.
The battery life mentioned by the manufacturer should be compatible with the features offered. You should carefully read the specifications for operating time and compare with similar units. You should also know that with radios, the transmission time (while you talk) is shorter compared to the ‘standby’ time (when the unit is idle).
Many of the handheld version of marine VHF radios presently offer GPS, AIS, WAAS, and GNSS positioning as well as plotting capabilities. Another point of comparison is the DSC capability or digital selective calling feature which is a significant safety tool that helps you to receive an MMSI or maritime mobile service identity number. Detailed information on this can be obtained here.
The unit to measure sound output is mW. When this is more you get a louder audio which can be important considering engine noise, wind and water noises. It is difficult to measure clarity. One way to check this feature before buying is to power up the unit you are considering and tune into a weather band. By adjusting the volume between full and silent you can understand this feature better.
A higher output power does not essentially translate to a higher range. VHF relies on a line of sight and therefore the range offered by nearly every handheld device theoretically remains the same. But a higher power rating in watts will ensure that the signals are heard better cutting through traffic from other radios in VHF frequencies that are increasingly cluttered. This is also one reason why courteous boatmen will switch to low power whenever the situation permits.
The newer radios come with a nice feature that enables charging via a USB and you can charge multiple electronic devices through this feature. Take care to ensure that charging cables for connecting to traditional 12-volt devices are also available. Alkaline batteries are acceptable with some radios and are added to the conventional rechargeable battery units.
Don’t get confused with internet protocol. For your marine VHF radio, IP codes represent international protection marking which denotes the level of protection against intrusion by water and dust. The rating is noted as IP with some numbers. The numbers denote the level of protection. The first number refers to protection from dust, the second indicates protection from water. If there is an X in place of a number that indicates the absence of any testing for the particular category. Thus, an IPX7 would indicate that the radio can withstand water immersion up to a depth of 1 meter and 30 minutes duration and that no testing has been done for dust intrusion.
Does a good mobile phone stand as a substitute
Unfortunately, the answer to this question is a firm NO. In open waters, mobile networks have a poor coverage and could even be non-existent in several locations. The DSC features and weather alert provided by marine radios are generally absent with cell phones and further, they are not waterproof. More importantly, marine radios are significantly more effective in facilitating rescue operations. Everyone in your range can be reached through a marine radio and anyone who hears the signal can home into your precise location. This feature is not available with any cell phone.