Two sailors spend dangerous night stranded at sea

Two Adelaide sailors have been rescued after spending more than 12 hours at the mercy of the sea in their stricken yacht.

The two men were on the nine-metre yacht called "Raucous Behaviour" when they struck trouble in the Spencer Golf around 4am in six metre waves.

"The engine stopped and they then had to turn it and go with the sea," one of the rescuers told 9NEWS.

The pair raised the alarm just off Hardwicke Bay but by 6.30am they were more than 30 nautical miles offshore.

A search plane from Melbourne tracked the boat from the air, while a nearby cargo ship was called in to escort the vessel.

A rescue mission was then launched, with the yacht intercepted by volunteer marine rescuers, near an island off  Port Victoria.

One of the men, a 64-year-old from North Haven, was suffering from hypothermia. The other man, in his late 50s, was also checked over by paramedics.

9NEWS understands they are both experienced sailors and were bringing the boat from Tumby Bay to Adelaide.