Provincial Police Commander, Chief Inspector David Yapu, said Bobby Pukel was travelling back to Tong Island after independence celebrations when he fell overboard.
Police allege that he and the skipper were drunk when leaving Lorengau town at 1pm on a 23-footer boat powered by a 40 HP engine.
PPC Yapu said the alarm was raised at the village and search was mounted at sea for five days but to no avail.
The boat operator who was with Pukel at that time is being questioned by police.
Yapu again warned boat operators and travelling passengers not to drink alcohol whilst out at sea.
“It is a serious criminal offence under the Small Craft Act for the operator of a small craft to operate whilst under the influence of alcohol or allows passengers to drink on board.”
Yapu has directed an investigation team to Tong Island to look into the incident.