Tools For Calling Mayday

Use these tools to call for help from your boat.

VHF — First Line of Defense
A VHF radio is your first choice to call for help, but it has limitations. Its range is dependent upon the gain and height of the antenna and the type of receiver. The Coast Guard maintains a 10- to 20-mile reach from shore in most areas. A fixed-mount radio and high-gain (9 db) antenna maximizes your range. When connected to a GPS and properly registered, your VHF's DSC button sends a distress signal, your location and your description to the Coast Guard. Bring aboard a handheld VHF as a spare, preferably a waterproof floating handheld like the Icom M24 ($179, icomamerica.com). Standard Horizon's innovative HX851 portable ($269, standardhorizon.com) combines a VHF and a GPS. If you venture beyond VHF range, invest in a long-range marine single-sideband radio or a satellite phone, like the Iridium 9555 ($1,295, iridium.com) or the Inmarsat IsatPhone Pro ($599, inmarsat.com).
Cell Phones at the Ready
Cell phones have limited and unpredictable range at sea and can't broadcast a mayday call. Your first thought is to call 911? Don't. That's for land-based emergencies. Instead, preprogram the phone numbers of the Coast Guard, harbor patrol and local services such as Vessel Assist or Sea Tow. Extend the range with a marine cellular antenna and wireless amplifier/repeater like those offered by Digital Antenna (digitalantenna.com). Still, don't rely on it as a first response.
EPIRBs — Worldwide Marine 911
As long as an EPIRB's antenna has an unblocked 360-degree view of the sky, its mayday signal can send your boat's information and location via satellite from almost anywhere. Personal locator beacons (PLBs) do the same, but are intended for an individual rather than the boat. PLBs typically transmit for 24 hours — an EPIRB lasts twice as long. Both are available with an internal GPS, which helps pinpoint your location and quicken response time.
AIS
Automatic Identification System (AIS) lets you "see" other AIS-equipped vessels on a chart-plotter screen. It displays vessel name, precise location, speed, heading, proximity to your boat and more. More importantly, with Class B AIS you can broadcast your exact location to all nearby AIS-equipped vessels. So in an emergency situation, they can more easily find you.
SART
A search-and-rescue radar transponder (SART), like the SA50 SART from Simrad ($800, simrad-yachting.com), when activated, will transmit a straight row of 12 blips to all radars in the vicinity. On the screen, those blips point like an arrow on the screen to your precise location.
Short-Range "Mayday" Tools
For close range, try a "marine hailer," like a Standard Horizon 240SW ($40) or even a megaphone. Man-overboard (MOB) alarm devices, like Raymarine's LifeTag ($600, raymarine.com), consist of personal transmitters and a shipboard receiver that sounds an alert when a crew member, or even a family pet, falls overboard. If all else fails, try a plastic whistle. ACR Electronics' WW-3 Res-Q rescue whistle costs $7 on amazon.com.

Nobody likes to think about calling for help on the water, but when the time comes, you better have the tools on board to make it happen. Here are some of the many ways to make sure your mayday is heard.