Maritime Survivor Locating Devices (MSLDs) are transmitters are intended for use by persons at risk of falling into the water such as mariners and workers on marine installations or docks, or by divers returning to the surface out of sight of their dive boats.


Maritime Survivor Locating Device (MSLD) rules were established in 2016.


Maritime Survivor Locating Devices (MSLDs) are licensed by rule.  This means an individual license is not required to operate a MSLD device. You can operate a MSLD device regardless of your age or citizenship.

The FCC service rules for Maritime Survivor Locating Devices (MSLDs) are located in 47 C.F.R. Part 95, Subpart K.


Maritime Survivor Locating Devices (MSLDs) must either:

  • Transmit on at least one of the following frequencies:  121.5 MHz, 156.525 MHz, 156.750 MHz, 156.800 MHz, 156.850 MHz, 161.975 MHz, or 162.025 MHz.;
  • Include a function intended to send a distress message directly to the U.S. Coast Guard or any other search and rescue organization.

Operating Maritime Survivor Locating Devices (MSLDs)

You can operate Maritime Survivor Locating Device (MSLD) in any place where the FCC regulates radio communications.  A MSLD must be certified by the FCC.  A certified MSLD has an identifying label placed on it by the manufacturer.
Use on land is not authorized.

How Maritime Survivor Locating Devices (MSLDs) Work

Maritime Survivor Locating Devices (MSLDs) can be worn on or as part of a garment or life jacket, and are intended to facilitate the rescue of personnel in the vicinity of their vessel or structure so that immediate assistance can be rendered without a time-consuming and expensive search and rescue operation.  MSLDs transmit on frequencies that are received on a device monitored by personnel at the MSLD-wearer’s vessel or facility.

Tuesday, September 27, 2022