The International Aeronautical and Maritime Search and Rescue Manual for Mobile Facilities provides guidance for the operation of vessels and aircraft for Search and Rescue (SAR) operations.
Three general level of command are used for coordination of rescue operations:
MAYDAY is reserved for grave and imminent danger and requests for immediate assistance.
PAN-PAN signal safety of a mobile craft is in jeopardy. It should be used when an unsafe situation exists that may eventually involve a need for assistance.
SÉCURITÉ is used for messages concerning safety of navigation, including important meteorological warnings.
Any message using one of these signal takes precedence over other communications. For other signals refer to the International Code of Signals (INTERCO).
Signal on 406MHz via Cospas-Sarsat satellites. Some devices also provide homing signal at 121.5/243.0MHz for directional RF location.
AIS-SART and AIS-MOB provide signals via AIS comms system.
Physical indicators include:
- red parachute flare
- red flare
- yellow smoke
- N over C flags
- square flag with ball under or over
- SOS (···---···) by light or sound
- slowly an repeatedly raising and lowering outstretched arms
Telemedical assistance services (TMASs) provide doctors experience with remote consulting for shipboard environments. Offered as a service on the RCC.
MEDICO messages request or transmit medical advice between vessels at sea and a TMAS
Medical evacuation (MEDEVAC) operations involve the extraction of sick/injured personal. If medical evacuations are being considered, the benefits must be weighed against the inherent dangers of such operations to both the person needing assistance and to the rescue personnel.
Three situations may occur involving a person overboard (MOB): 1. Noticed from the bridge with immediate action taken. 2. Reported to the bridge with a delay to action. 3. Person missing - occurred at unknown time or location.
Standard recovery procedures: - Williamson turn: bare away 60 deg, hard rudder in opposite direction and loop back to inverse path. - Anderson turn: single 270 deg turn and intercept. - Scharnov turn: inverse Williamson. Not suitable if location of incident is unknown as will miss section of path, but faster to perform. - Lorén turn: deploy rescue boat / float and circle to calm seas. Recover on leeward side.