SYDNEY (AFP) - The crew of an Antarctic cruise ship steaming to the assistance of a French sailor adrift on the Southern Ocean in a life raft were preparing Sunday for a delicate rescue operation in remote seas.

Alain Delord was attempting to sail solo and without assistance around the world when his yacht, Tchouk Tchouk Nougat, was damaged in rough seas off southern Australia's Tasmania island on Friday.

Delord was forced to abandon ship and has been adrift in a life raft on the Southern Ocean for more than three days.

Authorities were first alerted to his plight by a colleague on Friday morning and Delord activated his emergency beacon later that afternoon.

The Australian Maritime Safety Authority dropped him food, water, communications equipment and a survival suit on Saturday and diverted an Antarctic cruise ship, the PV Orion, to go to his rescue.

The Orion expects to arrive at Delord's location, some 500 nautical miles from Tasmania, on Sunday evening and AMSA said the rescue would be testing.

"I don't want to underestimate the difficulty of the task for the PV Orion - his cruise vessel is not designed for search and rescue," an AMSA spokeswoman told ABC Radio.

"It will be difficult for him to put down his own life raft and collect the sailor." The Orion's captain Mike Taylor said finding Delord would be his first challenge.

"A life raft is harder to see - it's a very big ocean out there," Taylor told Fairfax newspapers.

"Providing we can locate him, and that's a very big if, the plan is to launch a Zodiac (inflatable boat).... tethering the (Zodiac and life raft) together and pulling him into the Zodiac." Taylor said Delord was "probably not going to be walking" after three days in a life raft but the fact he had been able to collect the supplies dropped to him by air indicated he was "probably pretty agile and tough".

"It must have been a hell of a job to launch the raft in the kind of conditions he faced earlier on, so my assumption is he is going to be in a traumatised state," he said.

"If necessary we can use a rope and a pulley to haul him up to the door and in." Don McIntyre, expedition leader on board the Orion, said the crew was expecting the rescue to be challenging.

"The forecast is for 30-knot winds gusting to 40 knots and the seas will probably be around seven metres," he said.

AMSA said it had stayed in regular contact with Delord throughout Saturday night, with three commercial aircraft involved in the operation including two with French interpreters on board.

Delord, an experienced yachtsman, has been at sea since October last year and was reportedly following the route of the Vendee Globe round-the-world ocean race.