Introduction to

VHF Marine Radios

The airways are becoming increasingly congested as more boaters are using marine radios. Therefore, the importance of correct and proper radio procedures are mandated. If boaters follow proper procedures, marine band radios will serve the boating community safely and with less frustration.

An important rule to remember is that unless a radio transmission is directed to you or is a public service broadcast, all radio transmissions are confidential and are not to be used by you for any purpose. You should not repeat what you hear over the radio unless it is a distress call or public broadcast.

The purpose of this book is to help you learn radio procedures and Federal Communication Commission (FCC) regulations. Be sure to read the instruction manual on how to operate your radio's specific controls and settings.

VHF Marine Radios are available in portable hand-held units and stationary (mounted) models. These radios are intended for use by commercial and recreational boaters only. Use between parties on land is prohibited.

Most recreational boaters do not need a radio station license from the Federal Communications Commission (FCC). Licensing of recreational boats is discussed later in this book. Commercial vessels must have a FCC station license and radio operators on vessels for hire must be licensed by the FCC as a Marine Radio Operator (see Marine Radio Operator later in this book).

VHF radios have different transmitting powers which is a major factor in determining the distance you can communicate with other stations. The standard stationary radio (the one mounted in a boat) has a typical output of 25 watts, and ahand-held radio has between 4 to 6 watts of transmitting power. Therefore, the 25 watt radio will transmit a greater distance and should be used in an emergency instead of the 4 watt hand- held radio.

The distance a radio can transmit depends on different factors such as wattage, antenna height and weather conditions. It is also incorrect to assume one can receive or transmit well while in heavy seas, as the antenna does not stay in a vertical position.

To calculate the transmitting distance of your 25 watt radio, add the square root of the antenna height to the square root of the receiving antenna height and multiply that number by 1.22. For example, the transmitting distance of a radio with an antenna height of 15 feet and the receiving antenna at 8 feet would be, approximately, 8.18 nautical miles.

Remember, this will depend on weather conditions. As most mariners know, when the "skipping effect" occurs it is possible to hear communications hundreds of miles away. This phenomen is known as "tropospheric ducting" and is very common in Mexico and Southern California waters, as well as in the southeastern states, from Virginia to Florida.

Tropospheric ducting occurs when marine radio transmissions become trapped in warm air inversions, or ducts, that are lying above the cooler ocean air. It is not usual to communicate with someone hundreds of miles away, cruising off the Mexican coast, while you are boating off Long Beach, California.

You will notice that almost all marine radios have a one-watt, low power setting and a high power setting for maximum wattage output. If the boat you want to contact is in sight, first try the one-watt setting on your radio. Your radio will not transmit as far as if on the high setting and a handheld unit transmitting on one-watt will use less battery power. If everyone switched to one-watt when applicable, the airways would be open for more communications between boaters and far less congested. Remember to listen before transmitting to make certain you are not stepping on communications already in progress.

Whether you are communicating with a friend or the Coast Guard, proper radio protocols should be followed at all times. You cannot use offensive language at any time or cut into a conversation between other stations. Some people have a habit of shouting into the microphone, mistakenly assuming that this will send the transmission further. Another problem is speaking too fast for the listening person to understand the transmission or write down information.

You should hold the microphone a couple of inches away from your mouth and speak directly into it, using a normal tone of voice. Shouting into the microphone will not increase transmitting distance and the receiving station will hear only a garbled message from too much gain.

Remember, marine radios transmit and receive differently than telephones or cell phones. Only one station can transmit at a time. In other words, you listen while the other person talks and visa versa. This is why such terms such as "out" and "over" are necessary. Never use the police 10 codes such as "10-4" or CB lingo ("breaker-breaker, good buddy", etc.)

When you have finished transmitting and are expecting a reply, say "over" and then release the transmit button.

When you have finished communicating with the other station completely and do not expect to transmit again, say "out" or "clear" as your final words.

The phrase "over and out" is used only in the movies or by novice radio operators. Saying "over" means you are expecting a reply, yet you have stated "out", meaning you have finished your transmissions.

You will also hear the phrases "roger," "affirmative" and "negative". Many boaters fail to distinguish between "roger" and "affirmative". "Affirmative" means yes, you understand and agree with the message received or heard. "Roger" means you have received the message but may not necessary agree with what was said. Therefore, "roger" is just an acknowledgement to the other station that the message was received. "Negative" is universally understood as no and that you do not agree with the message or answering a question.