Although marine VHF radios are currently not a requirement for small recreational boats, this should be high on your list of equipment to carry. You should learn to properly use the radio and, during your passenger orientation, make sure at least one of your guests can also use the radio in case of emergency.
Distress is defined as a situation where you or your boat are threatened by grave danger with loss of life or of the watercraft being imminent. Running out of fuel, a dead battery or other mechanical problems are not distress situations.
The Coast Guard serves as Search and Rescue (SAR) coordinator for all maritime emergencies and is the appropriate point of contact whenever you are concerned for your safety. If you are in distress, the Coast Guard will take immediate steps to help you. Normally Coast Guard rescue boats and/or aircraft will be sent, but assistance from any available source will be arranged to expedite your rescue.
First you need to be familiar with just a few of the many radio channels available to you. Channel 16 is the hailing and emergency channel. This means that this channel is used to hail (call) another boat, marina, the U.S. Coast Guard, etc. You should not hold conversation on this channel. In non-emergencies use it only to contact another party and then switch to a "working channel" to carry on your conversation. There are many working channels to choose from. Just pick one, say Channel 68, and use it regularly. Another channel to remember is Channel 22A. This is the U.S. Coast Guard's channel. Although you can contact them directly from Channel 16, you can also contact them on 22A.
If you are in distress use "MAYDAY, MAYDAY, MAYDAY" on the radio. If your situation is not a distress, simply call "Coast Guard." Channel 16 VHF/FM and 2182khz HF/SSB are dedicated distress and calling frequencies and are monitored at all times by the U.S. Coast Guard.
Citizen's Band (CB) is not dependable and is not monitored at most Coast Guard stations. If you do not have a radio, attempt to signal a fellow boater who can assist or call the Coast Guard for you. In a distress situation, use flares or any other distress signaling device to catch the attention of another boater.
While arranging help, the USCG will ask for the following:
The Coast Guard's primary search and rescue role is to assist boaters in distress. If you are not in distress and alternate sources of assistance are available, you should try to contact them directly. If you can not raise alternate assistance directly, the USCG will normally coordinate the effort to assist you. If you have a friend, marina, or commercial firm such as a towing company that you want contacted, they will attempt to do so.
The Coast Guard does not advocate cellular phones as a substitute for the regular maritime radio distress and safety systems recognized by the Federal Communications Commission and the International Radio Regulations -- particularly VHF maritime radio. However, cellular phones can have a place on board as an added measure of safety.
There is no comparison between cellular phones and VHF marine radio. They provide different services. The cellular phone is best used for what it is, an onboard telephone -- a link with shore based telephones. A VHF marine radio is intended for communication with other ships or marine installations -- and a powerful ally in time of emergency.
If you have a portable or handheld cellular telephone, by all means take it aboard. If you are boating off shore, a cellular phone is no substitute for a VHF radio. But, if you are within cellular range, it may provide an additional means of communication.