FIVE men have been winched to safety by RACQ CareFlight Rescue after their catamaran capsized off the northern end of Fraser Island.
It is understood water flooded the vessel and the engine failed, causing it to overturn.
The Bundaberg RACQ CareFlight Rescue helicopter responded to the incident at 3pm Sunday after a distress beacon was detected by the Australian Maritime Safety Authority (AMSA).
A Royal Australian Air Force (RAAF) C-130J Hercules and a Water Police vessel from Hervey Bay were also tasked by AMSA to respond.
CareFlight's rescue crew located the stricken vessel north of Sandy Cape.
RACQ CareFlight Rescue's Aircrewman was lowered into the water to secure each man into a rescue strop before they were winched on board the rescue helicopter.
Two men were winched from the water first and dropped off on the beach with the Flight Intensive Care Paramedic.
The helicopter then returned to the stricken vessel to pluck the remaining three men from the ocean.
All five men were then transferred to Orchid Beach on Fraser Island.
The men, believed to be aged in their 30s, had been in the water for about two-and-a-half hours.
They were a bit shaken up but otherwise unharmed.