From VHF radio to ham radio, boaters have several options for communicating with other boats or the shore.
While convenient for conversations with those on land, cell phones can’t be relied on for on-the-water emergencies. The U.S. Coast Guard and other search-and-rescue agencies cannot direction-find emergency cell phone calls, and coverage is limited by the location of land-based relay towers.
VHF radio remains the nearshore boater’s first choice for emergency calls and routine communications. VHF emergency channels are constantly monitored. Although VHF boat-to-boat transmissions are limited to about 20 nautical miles (less between powerboats with low antenna heights), ship-to-shore calls may be possible up to 30 miles out because of taller shore-based antennas.
Single-sideband radio is used for ship-to-ship and ship-to-shore communications beyond VHF range. SSB high-frequency radio waves reflect from the ionosphere, allowing them to reach transceivers thousands of miles away under the right propagation conditions.
With shorter ranges of 150 to 200 miles during the day or as much as 500 miles at night, medium-frequency SSB signals (called groundwaves) wrap around Earth’s surface. SSB radios can also receive worldwide weather broadcasts and email services.
Although expensive, satellite phones offer reliable voice, fax, email and data communications around the world. One company, Inmarsat, supports regular and emergency distress calls (except in polar regions) by using satellites in geostationary orbit. Iridium and Globalstar provide satellite coverage using low-orbiting satellite networks.
Ham radio (amateur radio) remains popular among cruisers. Licensed ham operators can speak with other licensed hams on land or sea and can ask a shore-based ham to patch them through a telephone line without paying the stiff fees charged by SSB high seas marine operators.
The General Class License required for voice communications over ham frequencies requires some knowledge of radio theory and ham operating protocol; however, passing the exam is not difficult. Ham radio equipment is less expensive than SSB equipment, though they operate at similar frequencies and over similarly impressive distances.
Although they don’t allow two-way communications, portable emergency position-indicating radio beacons can be activated aboard a distressed vessel or in the water to summon help offshore. EPIRB signals are relayed via satellite to search-and-rescue centers. Modern EPIRBs identify the boat from which they came and provide GPS coordinates to rescuers.
To learn more, take the Using VHF/DSC Marine Radio seminar at a squadron near you.