If you're making a list of essential equipment for your boat, a good-quality VHF marine radio belongs near the top.

"When people ask me about buying a radio, I tell them it's a little like that slogan they used to use in those credit card ads–"˜Don't Leave Port Without It,'" says Jim Welday, a radio communications watch stander at the Coast Guard station in Annapolis, Maryland.

Welday, who also goes on boater-assistance patrols with the Coast Guard Auxiliary, recently rescued a boater who had been stuck on a shoal in heavy weather for two and a half hours before the patrol boat finally spotted him. "We asked why he didn't just radio us, because we could have been there within a few minutes," Welday says. "But he said he didn't have a radio. I couldn't believe it."

If you're injured, are experiencing serious engine trouble, or have run aground and need a tow, you need to get help–fast. Calling for help on a VHF marine radio reaches all first-responders–the Coast Guard, marine police and commercial towing services–and may also net you assistance from a nearby boater, who can get to your vessel much faster.

ICOMMounted VHF radios generally output 25 watts of power and can transmit about 20 miles along line of sight. A quality antenna, mounted as high as you can get it, will help.

To use a cell phone would require loading it with direct-dial numbers for the Coast Guard, the fire department, towers and the harbor police–and you would miss reaching nearby boaters, because cell phones can call only one source of help at a time and coverage often is spotty. Call for help on a CB (citizens' band) radio, and you'll most likely reach a trucker. The Coast Guard doesn't even monitor CB channels, and few well-equipped boats have CB radios at all.

EASY ON YOUR WALLET

Fortunately, you don't have to take out a second boat loan to afford a marine radio. Boating supply stores routinely sell them for between $100 and $600, depending on the quality and extra features you want. And they're often on sale.

There are two basic categories of VHF-FM marine radio: a fixed-mount model that's installed permanently in your boat, or a battery-powered hand-held version that you can take with you wherever you go. The fixed-mount radio usually puts out 25 watts of power and can transmit (along line-of-sight) up to about 20 miles. The hand-held puts out between one and six watts of power and transmits about four or five miles.

It doesn't take a technician to recognize the difference: the fixed-mount is best because it has a longer range; the hand-held is okay for calling marinas or nearby boats, taking in the dinghy or using as a second listening-post. The best scenario is to have one of each, and use the hand-held as a backup in case the fixed-mount model malfunctions or your boat loses electrical power.

Be sure to mount your antenna as high as you can–atop the mast, for those who own sailboats, and on the flying bridge or radar arch for power boaters. The higher the antenna, the better your transmission and reception.

Unless you're venturing far from home, a garden-variety radio ought to be sufficient. If you want to spend a little more, buy one of the new models that has DSC (digital select calling), a device that links to your GPS receiver. When you push an emergency button, it alerts the Coast Guard to your exact position and gives rescuers a detailed description of your boat. To activate this feature, you must register your DSC radio, which can be done free through BoatUS, which will pass that information on to the Coast Guard and the Federal Communications Commission.

Another useful extra is a remote microphone that you can install in your cockpit or, with a hand-held radio, clip to your shirt-pocket. The mike contains an extra speaker and has command buttons that you can use to change channels and control the volume without having to go back to the main radio set. Some marine radios have built-in loud-hailers–a kind of electronic megaphone–so you can project your voice to another boat without actually having to go on the air.

HOW TO USE IT

But simply buying a radio doesn't fulfill your responsibilities when it comes to communications about safety. You need to know how to use it properly as well.

Read the directions that come with the radio you buy. After turning the radio on, select the channel you want to use and adjust the "squelch" button, which helps minimize static and background noise. If you want the radio to keep scanning selected stations until it reaches one that has voice traffic on it, learn how to program and use the "scan" button. To speak, key the handset by pressing the square or oval shaped button that sticks out at the side of the microphone, hold the mike two to three inches from your mouth, and speak in a slow, steady voice. Don't yell and don't whisper.