The AIS-SART is a self contained radio device used to locate a survival craft

Lifeboat (shipboard)

A lifeboat is a small, rigid or inflatable watercraft carried for emergency evacuation in the event of a disaster aboard ship. In the military, a lifeboat may be referred to as a whaleboat, dinghy, or gig. The ship's tenders of cruise ships often double as lifeboats. Recreational sailors sometimes...

 or distressed vessel by sending updated position reports using a standard Automatic Identification System

Automatic Identification System

The Automatic Identification System is an automatic tracking system used on ships and by Vessel traffic services for identifying and locating vessels by electronically exchanging data with other nearby ships and AIS Base stations...

 (AIS) class A position report. The position and time synchronization of the AIS-SART is derived from a built in GNSS receiver (e.g. GPS).
Shipboard Global Maritime Distress Safety System

Global Maritime Distress Safety System

The Global Maritime Distress and Safety System is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft....

 (GMDSS) installations include one or more search and rescue locating devices.
These devices may be either an AIS-SART (from 1.January 2010) (AIS Search and Rescue Transmitter), or a radar-SART (Search and Rescue Transponder).

The AIS-SART derives position and time synchronization from a built in GNSS receiver and transmits its position with an update rate of 1 minute. Every minute the position is sent as a series of eight identical position reports, this is to maintain a high probability that at least one of the position reports is sent on the highest point of a wave.

AIS SARTs are typically cylindrical, and brightly colored. A typical model is 251mm (about 10 inches) high and weighs 450g (about a pound).

The specification for the AIS-SART has been developed by the IEC (International Electrical Committee), TC80, AIS work group.
The AIS SART was added to the GMDSS regulations effective January 1, 2010. http://www.ship-technology.com/contractors/navigation/jotron/press1.html

See also

• Emergency Position-Indicating Radio Beacon
  Emergency Position-Indicating Radio Beacon
  Distress radio beacons, also known as emergency beacons, ELT or EPIRB, are tracking transmitters which aid in the detection and location of boats, aircraft, and people in distress. Strictly, they are radiobeacons that interface with worldwide offered service of Cospas-Sarsat, the international...
  
   (EPIRB)
• Civil Air Patrol
  Civil Air Patrol
  Civil Air Patrol is a Congressionally chartered, federally supported, non-profit corporation that serves as the official civilian auxiliary of the United States Air Force . CAP is a volunteer organization with an aviation-minded membership that includes people from all backgrounds, lifestyles, and...
  
   (US Air Force Auxiliary)
• Marine VHF radio
  Marine VHF radio
  Marine VHF radio is installed on all large ships and most seagoing small craft. It is used for a wide variety of purposes, including summoning rescue services and communicating with harbours, locks, bridges and marinas, and operates in the VHF frequency range, between 156 to 174 MHz...
  
  
• Automatic Identification System
  Automatic Identification System
  The Automatic Identification System is an automatic tracking system used on ships and by Vessel traffic services for identifying and locating vessels by electronically exchanging data with other nearby ships and AIS Base stations...
  
  
• Global Maritime Distress Safety System
  Global Maritime Distress Safety System
  The Global Maritime Distress and Safety System is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft....