VHF, AIS and chartplotters.

VHF radio

A Coast Guard Auxiliary author, writing on the Atlantic Maritime Academy site, says handheld VHFs typically transmit at 5 W and fixed-mount radios at 25 W, and that range depends mainly on antenna height. The author's examples: a handheld held about 2 m up reaches about 5 km, and a fixed antenna about 15 ft above the water reaches about 14 km. Boating Magazine makes the same point from the other side: VHF is line-of-sight, so most handhelds have similar range.

For a handheld, Boating Magazine recommends IPX7 waterproofing, a radio that floats or comes in a flotation case, more than one way to charge it, and DSC with GPS. US Sailing's 2025.2 nearshore racing requirements call for a VHF, fixed or handheld.

Do you need a licence?

Boat-Ed, a provider of state boating courses, says most recreational boats used only in US waters have not needed an FCC Ship Station License since 1996. It says a licence is still needed for international voyages, including to Canada and Mexico, and for powered vessels over 65.6 ft (20 m). We did not read the FCC regulation itself, so confirm your situation with the FCC.

DSC and the MMSI

Digital Selective Calling lets a radio send a digital distress alert. The Coast Guard's 2024 DSC article explains how it works: pressing the red distress button sends an alert that identifies the vessel and, if the radio has a GPS position, its location, and repeats about every four minutes until acknowledged. The article also says:

• A DSC radio must be programmed with a nine-digit Maritime Mobile Service Identity (MMSI), or responders will not know who is calling.
• It needs a built-in or connected GPS to send a position. The Coast Guard recommends buying a radio with internal GPS.
• The Coast Guard keeps a DSC watch on channel 70 and a voice watch on channel 16 (156.8 MHz). Its Rescue 21 system covers about 90% of the US coast out to about 20 nautical miles.
• The Coast Guard asked the FCC to require DSC on type-accepted marine radios installed on US vessels from June 17, 1999.

How to actually make a distress call is radio procedure that belongs in a course, not on a web page.

Getting an MMSI

According to BoatUS, it issues MMSIs for US recreational vessels under 65 ft that do not visit or call at foreign ports, and passes the data only to the Coast Guard's database. Cruising abroad requires an FCC Ship Station License with an FCC-issued MMSI, which ends in zero. FCC-issued MMSI details are public and appear on vessel-tracking websites; BoatUS registration data is not shared with them.

BoatUS also warns that pressing the distress button as a test is illegal. Instead it describes making a test call to the Coast Guard's MMSI, 003669999, on channel 70. Two boats must never share an MMSI, and the number should be transferred or updated when a boat or radio changes hands.

AIS

AIS (Automatic Identification System) broadcasts a boat's position and MMSI to other AIS users; BoatUS notes that both Class A and Class B units do this. The Coast Guard Navigation Center says 33 CFR 164.46 requires Class A AIS on certain commercial vessels, such as self-propelled commercial vessels of 65 ft or more and vessels certified for more than 150 passengers. The page states no requirement for recreational boats.

A recreational boat may fit Class A or Class B AIS if it is FCC-certified, but the Navigation Center says that once installed it must broadcast accurate information at all times, with penalties of up to $25,000 for failing to.

Class B units come in two types, CSTDMA and SOTDMA. Panbo says a CSTDMA Class B transponder reports every 30 seconds, and the newer SOTDMA Class B transmits at 5 W, more than twice the CSTDMA power. A manufacturer commenting on Panbo claims SOTDMA also gets priority in reserving transmit slots and reports faster at higher speeds.

Chartplotters

Sail Magazine calls chartplotters and multifunction displays virtually indispensable. Networked with GPS, AIS and radar over NMEA 0183 or NMEA 2000, they show that data in real time. It notes that many units have touchscreens but keep hard keys or offer a remote for rough conditions, and advises buying the largest screen that fits and checking compatibility with your existing instruments.

US Sailing's nearshore requirements still call for a compass that works independently of the boat's electrical system.

The end of NOAA paper charts

NOAA finished retiring its traditional charts in December 2024. It cancelled the last of its 1,007 paper charts along with its raster charts (RNC/BSB), chart PDFs and BookletCharts. Its Electronic Navigational Charts (ENCs) are now its main product: vector data, updated every weekday evening, and being reorganized into a regular grid of about 9,000 cells at 12 scales.

Paper is still possible. NOAA says you can print charts through NOAA Custom Charts, which builds PDFs from current ENC data. For how charts and instruments are used together, see navigation.