In a brief, Namatanai police said the passenger double-engine boat, loaded with 13 passengers, left Kokopo, East New Britain Province, at about 5.30pm.
The boat ran out of fuel when it neared Burau village, Namatanai.
The rough seas rushed into the boat, forcing passengers to jump out and try to make it to the reef.
“Darkness was just falling when people were struggling in the rough seas as there were no lifejackets or pads on board,” said the Namatanai acting police station commander, Nambulasa Silau.