The Panamanian-flagged phosphate ship MV Tycoon has sunk in rough weather in the cove on Christmas Island, sending phosphate across the reef and damaging the crane that loads supplies to residents and the island's detention centre.

The ship remains visible but its hull is sitting on the bottom of the cove after a night smashing against the island's jagged cliffs. It is monsoon season on the island and the waves are treacherous.

It is unclear yet if the island's cargo crane was damaged in the accident.

An engineer is due to fly to Christmas Island from Perth tomorrow to assess and repair the crane if necessary.

A supply ship due to dock at Christmas Island today was unable to unload cargo because of the potential damage and the dangerous seas. The ship, which makes the voyage to Christmas Island every six to eight weeks, is carrying foodstuffs and other supplies.

If the crane unable to operate, Christmas Island residents could run short of essential supplies, a source said, but the island's detention centre has sufficient stores to last several weeks.Residents say the stench of diesel from the vessel is overpowering and worry about the effect on the island's iconic red crabs the baby crabs are due to return to the cove soon as part of the annual migration.

Yesterday the crew was forced to jump into the ocean to waiting navy rescuers.

The 100m-long vessel broke its mooring and suffered damage down one side of its hull as it tore against the rocks.

None of the 15 crew was injured. They were taken to shore and given temporary accommodation last night.