EPIRB, PLB & Distress Beacons

Printable checklist: Launch day

When voice radio is out of range or the boat is going down, a 406 MHz satellite distress beacon—an EPIRB (Emergency Position Indicating Radio Beacon) or a PLB (Personal Locator Beacon)—can alert search-and-rescue through the international COSPAS-SARSAT system. The U.S. Coast Guard Boaters Guide and NOAA SARSAT describe these as tools that quickly alert rescue personnel, pass a distress position, and help units home in—even when other communications fail.

This page summarizes the USCG Boaters Guide (EPIRBs/PLBs, SARSAT, radio licensing, DSC), NOAA SARSAT 406-beacon / registration / testing / false-alert pages, the FCC Personal Locator Beacons page, and Discover Boating distress-signals and emergency-preparedness pages only. Those sources do not publish brand rankings, price tables, or “best kit” lists—so we do not invent those here. Pair this guide with VHF marine radio basics (Channel 16 and DSC), AIS basics for recreational boaters (being seen vs calling for help), visual distress signals and flares, the short carriage overview in required safety equipment by length, the printable Launch Day checklist, and State Rules for state overlays.

EPIRB vs PLB vs VHF DSC (high level)

Tool What it is (from official pages) Typical recreational use
VHF + DSC Ship-to-ship / ship-to-shore radio; DSC can send a formatted distress alert when GPS and an MMSI are set up First call for help when you are in VHF range of the Coast Guard or other vessels (Boaters Guide; Discover Boating emergency prep)
EPIRB 406 MHz beacon designed for maritime use; Category I can float free and auto-activate; Category II is manual Vessel-mounted beacon that stays with the boat / life raft and talks to satellites when radio may not reach anyone (NOAA SARSAT; Boaters Guide)
PLB Compact 406 MHz personal beacon; manual activation only (NOAA; FCC) Worn or carried by a person—paddlers, hunters, or crew who may leave the boat or boat alone far from VHF coverage (NOAA; FCC)

They are complementary, not substitutes. Discover Boating’s emergency-preparedness page still puts VHF Channel 16 and visual distress signals in the call-for-help sequence. The Boaters Guide treats EPIRB/PLB as part of emergency alert/communications alongside radio. Annex IV / Rule 37 distress signals (Discover Boating distress-signals page) list EPIRB among recognized distress signals—separate from the coastal visual distress signal carriage rules in visual distress signals and flares.

How 406 MHz / SARSAT works (high level)

From the Boaters Guide and NOAA SARSAT:

  • An international satellite constellation listens for 406 MHz distress signals.
  • NOAA operates satellites, ground stations, and alert distribution for the United States and much of the international community.
  • When activated, the beacon sends a distress signal with a beacon-unique identifying code. The system calculates a position, checks that code against the registration database (vessel / owner contact info), and routes the alert to the responsible U.S. Coast Guard or international Rescue Coordination Center (RCC).
  • Beacons with GPS (internal or externally supplied) can pass an immediate GPS position; geostationary satellites can make detection almost immediate. Without GPS position capability, the Boaters Guide says determining a position takes about one hour on average and almost always less than two hours.
  • Satellite EPIRBs also include a homing beacon and strobe to help rescuers find the scene.
  • NOAA: 406 MHz is the frequency satellites use for distress. Satellites have not detected 121.5 MHz distress signals since 2009—do not rely on old 121.5-only gear for satellite alerting.

EPIRB categories (maritime)

NOAA SARSAT (emergency 406 beacons page):

  • Category I: Manual or automatic. Housed in a bracket with a hydrostatic release. When the vessel sinks to about 3–10 feet, the EPIRB ejects, floats free, and begins transmitting. Mount it outside the cabin where it can float free of a sinking vessel.
  • Category II: Manual activation only. Store where it can be reached quickly in an emergency.
  • Both types are designed to float and include a built-in strobe. NOAA states EPIRBs transmit for at least 48 hours once activated (also: battery life in immersion conditions of 48 hours or more on the same page). We do not invent other run-time or brand figures.

Boaters Guide: mount to float free per the manufacturer’s instructions when possible; otherwise keep it readily accessible. Register with NOAA (mandatory; improves response time; reduces false alarms).

PLBs (personal)

NOAA SARSAT: PLBs are portable units for an individual—often cell-phone sized—suited to remote travel (including kayakers and canoeists). They activate only manually and operate on 406 MHz. Some include GNSS so the distress message carries a GPS-encoded position; NOAA describes that as improving location accuracy to about the 100-meter level. NOAA states operational battery life once activated is 24 hours minimum. We do not invent other battery or range claims.

FCC (Personal Locator Beacons page, updated 2023-04-07):

  • PLBs transmit personalized distress signals in the 406–406.10 MHz range to COSPAS-SARSAT.
  • Rules are in 47 C.F.R. Part 95. PLBs are licensed by rule—no individual license is required (any age or citizenship).
  • The device must be FCC-certified (manufacturer label).
  • Each PLB must be registered with NOAA so search-and-rescue has emergency contact information.
  • Each unit has a unique 15-character (alphanumeric) identifying code linked to the NOAA database.

Registration (mandatory for U.S. 406 beacons)

NOAA Why Register / Beacon Registration portal / Boaters Guide:

  • If you buy a new or used U.S.-coded 406 MHz beacon, you must register it with NOAA (required by law; solicitation authority cited on the registration site includes Title 47 Parts 80.1061, 87.199, and 95.2993).
  • There is no fee for U.S. Government registration. If anyone asks you to pay to register, contact beacon.registration@noaa.gov (portal notice).
  • Register online at the NOAA Beacon Registration database, or use the printable form (mail/fax options on NOAA’s Why Register page). Toll-free: 1-888-212-SAVE (7283).
  • Update the registration when contact info, boat, or ownership changes. If you sell the beacon, notify NOAA and tell the buyer they must register it—or you may get the rescue call when it activates.
  • Registration is valid for two years; re-register every two years so contact records stay current (NOAA).
  • NOAA’s database accepts U.S.-coded country codes only (contiguous U.S., Alaska, Hawaii, Puerto Rico, U.S. Virgin Islands, Northern Marianas, American Samoa—codes listed on the Why Register page). Non-U.S.-coded beacons register elsewhere (contact the manufacturer).

Testing and false alerts

NOAA Beacon Testing / Preventing False Alerts:

  • Use the beacon’s self-test mode per the manufacturer. Self-test does not require NOAA approval; it broadcasts a specially marked test signal that ground stations ignore.
  • Live activation (other than approved self-test) is treated as distress. Live testing needs national-sponsor validation and NOAA approval via a 406 MHz Beacon Test Request—do not “try” a live alert.
  • Accidental activation: NOAA says call the U.S. Coast Guard for an EPIRB (1-855-406-8724), and the U.S. Air Force for an ELT or PLB (contacts on the Preventing False Alerts / testing pages). Canceling promptly matters so SAR resources are not diverted.

VHF DSC and MMSI (high level only)

A beacon does not replace learning VHF Channel 16 / MAYDAY and DSC. From the Boaters Guide (high level):

  • DSC can send an automatically formatted distress alert when the radio is DSC-capable, linked to GPS, and programmed with an MMSI.
  • Recreational boats that voluntarily carry VHF in U.S. waters can get a domestic MMSI through approved organizations the Boaters Guide lists (for example BoatUS, U.S. Power Squadrons / America’s Boating Club, Shine Micro for AIS). Details and current signup paths belong on the FCC / those program pages—we do not invent steps here.
  • Most recreational vessels under 65.6 feet (20 m) are not required to carry a marine radio; if you carry one, follow FCC procedures. The Boaters Guide: the FCC does not require most recreational operators to have an individual license to operate VHF-FM marine radios, EPIRBs, or radar for typical domestic use—but follow licensed-operator courtesies in the FCC rules.

Honest gaps

  • No brand picks, kit rankings, or price tables appear on the allowed pages.
  • Battery run-times cited above are only the minimums NOAA publishes (PLB ≥24 h; EPIRB ≥48 h). Check your unit’s label and manufacturer instructions for the rest.
  • Exact hydrostatic-release service intervals, bracket part numbers, and state-by-state carriage mandates beyond federal recreational carriage (EPIRBs/PLBs are not listed as universal federal carriage items like PFDs/VDS in the Boaters Guide equipment chapters we used) are not tabulated here—confirm commercial / inspected-vessel rules and your State Rules separately.
  • USCG Navigation Center EPIRB homepage and some FCC maritime URLs returned 403/404 to our fetcher this run; we relied on the Boaters Guide, NOAA SARSAT, and the FCC PLB page that did load.

Book a free Vessel Safety Check with the Coast Guard Auxiliary. Budget a registered 406 beacon alongside radio and visual distress gear in the True Cost tool if you are still outfitting. Put registration renewal and self-test on the same pre-season pass as spring commissioning and Launch Day.

Sources

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