Candidates most often trip up by conflating EPIRBs with SARTs, muddling frequencies, and giving vague answers about testing procedures. Examiners want specifics — how a device works, how you prove it works, and how you use it under pressure.
EPIRB
An Emergency Position-Indicating Radio Beacon transmits on 406 MHz (detected by COSPAS-SARSAT satellites) and simultaneously on 121.5 MHz as a homing signal for SAR aircraft and vessels. Activation — manual or automatic on water immersion — sends a coded signal containing the vessel's MMSI/registration, allowing RCC to identify the vessel without a voice call. The 406 MHz signal provides position to satellite; many modern EPIRBs also incorporate an internal GPS to transmit a precise position within the coded message, dramatically reducing search area.
Testing: Modern 406 MHz EPIRBs have a dedicated self-test mode that does not transmit a live distress signal. Carry out the self-test in accordance with the manufacturer's procedure and the vessel's planned maintenance schedule. Check the service/battery expiry label — both the hydrostatic release mechanism and the battery have finite service lives. Confirm registration is current with the national authority.
SART
A Search and Rescue Transponder operates on 9 GHz X-band radar. When triggered, it responds to any X-band radar sweep by transmitting a series of 12 dots on the radar display, expanding to 12 arcs as the searching vessel closes range. SARTs do not communicate position to satellites; they only respond to active radar interrogation. A SART test is conducted by activating it in test mode and sweeping with a vessel radar — confirm the pattern appears. The SART also has a visual indicator (flashing light) and audible beep when being interrogated.
AIS-SARTs and PLBs are increasingly fitted; understand they operate differently (AIS-SART transmits on AIS frequencies, appears as a target on ECDIS/chart plotter).
Immersion Suits
Must be donned in under two minutes without assistance (LSA Code 2.3.1.1). Inspect regularly for: zip integrity, seals at wrists and face, reflective tape condition, whistle and light attachment. The suit maintains a survival body-core temperature in cold water, but candidates must know the suit does not guarantee survival — sea state, prior cold shock and cardiac response all affect outcome. Size and correct fit are critical; a suit that does not seal properly will flood.
Line-Throwing Appliance
Used to establish a connection between vessel and casualty or shore. Rocket-propelled types must carry at least four projectiles and four lines, with a line breaking strength of no less than 2 kN (per LSA Code Chapter VII). The appliance must be capable of throwing a line to a range of approximately 230 metres in calm weather. Handle with care — they are pyrotechnic devices. Crew must be briefed on aim point (slightly above and beyond the target to allow the line to drop across), and the target's crew must be instructed to haul in carefully.