More than 200 boats and 500 people spent Memorial Day partying on the sandbar known as Ahu o Laka in Kaneohe Bay, officials estimated.

Deborah Ward, spokeswoman for the state Department of Land and Natural Resources, said enforcement officers boarded 15 vessels in Kaneohe Bay and issued 15 warnings for safety violations, such as for operating in areas reserved for personal watercraft.

Officers also checked people on the sandbar for underage drinking and broke up a fight at about noon involving two men, Ward said. No arrests or citations were issued.

The Coast Guard said one boat owner was cited because the boat was over capacity and did not have enough life jackets to accommodate all on board.

The Department of Land and Natural Resources had seven enforcement officers at Kaneohe Bay, the sandbar and Heeia Small Boat Harbor, Ward said.

Three were assigned to Heeia Pier, and four were on two patrol boats at Ahu o Laka or in the bay, Ward said.

Two men were involved in a fight at Heeia Pier at about 6 p.m. Monday, sending one of them to the hospital in critical condition.

Police said the assailant punched the other man, who fell and hit his head on the asphalt. The victim, who is in his 20s, apparently also had a cut on his cheek from the punch.

Police opened a second-degree assault case.

At low tide about three acres of sand at Ahu o Laka, which is considered state land, are exposed.

There have been calls to prohibit drinking at the sandbar, require permits for concerts, ban concerts and make it a bird sanctuary.