AIS S.A.R.T emergency transmitters send the GPS position data of a person overboard to all vessels with AIS receivers / AIS transponders in the vicinity. The recipients of the emergency call are made aware of the emergency situation by a special SART signal on their AIS receiver/plotter. In contrast to AIS MOB emergency location systems, AIS S.A.R.T emergency transmitters are designed for life rafts. AIS S.A.R.T emergency transmitters have a longer antenna and a greater service life than AIS MOB transmitters. They are usually triggered manually.