All 15 crew have been rescued from a sinking offshore support vessel (OSV) off the US.

The 500-gt life boat Ram XVIII (built 2015) started taking on water on Sunday off Grand Isle, the US Coast Guard said, according to the Nola website.

The USCG took nine people off the vessel and the 400-gt OSV Starfleet Guardian (built 2015) picked up the other six.

The master reported that the vessel had a 45-degree list and no power.

A steel tank filled with soap fell over the side, causing slippery and hazardous conditions.

The ship also has about 13,900 gallons of diesel on board, but there have been no reports of pollution.

An investigation has begun.

The vessel is operated by Aries Marine Corp.