File image of a P-8A Poseidon. (Defence)

A Royal Australian Air Force (RAAF) Boeing P-8A Poseidon has taken part in a search and rescue mission for the first time, when an aircraft on a routine training mission responded to a mayday call from a stricken dolphin cruise boat.

The MV Port Princess issued a mayday call at around 1pm on May 16 when off the South Australian coast near Port Macdonnell after the vessel had begun taking on water following an engine failure.

The RAAF P-8A, callsign ‘Blackcat 20’, intercepted the mayday call and assisted the rescue of the MV Port Princess’s four crew by providing communications assistance and relaying realtime imagery of the vessel to the Australian Maritime Safety Authority’s Rescue Coordination Centre in Canberra.

The crewmembers were rescued by a fishing boat from Port Macdonnell, before the Port Princess, which was in transit from Port Adelaide to a new owner in Victoria, sank.

“This is the first search and rescue response completed by the P-8A Poseidon since the aircraft’s arrival into Australia last November. The Poseidon is still undergoing test and evaluation activities before a formal introduction into service,” executive officer for 92 Wing, Wing Commander Brett Williams, said in a statement.

“Search and rescue forms an important part of the operational test and evaluation program which we’ve laid out to bring the Air Force’s P-8A Poseidon into service.”

An image grab from the P-8A that assisted with the coordination of a search and rescue response. (Defence)