JEFFERSON -- A family outing on a pontoon boat in Lake Hopatcong ended tragically Saturday afternoon after a man in the boat drowned while retrieving his hat from the water, State Police said.

Bo Long, 51, of Livingston, turned the boat around after his hat blew off, shut off the engine and jumped into the water, State Police Lt. Ted Schafer said.

Long managed to reach his hat, but by then the boat was drifting away, Schafer said.

Up to 10 passengers, believed to be family members, were aboard. Long was not wearing a life jacket, Schafer said.

"After several minutes, he had difficulty swimming," Schafer said.

Two passengers jumped in after Long slipped below the surface but were unable to rescue him, Schafer said.

State police and other rescue personnel responded after receiving a 911 call at 4:13 p.m.

The caller, John Brinton, was on a jet ski and provided assistance along with a second jet skier, David Schmidt, Schafer said.

Schafer did not know exactly who pulled Long from the water, but said that state police, Jefferson police and Jefferson first aid squad members responded.

Efforts to revive Long failed and he was pronounced dead at some point after being brought to shore, Schafer said.

The boat was rented from Bridge Marina.

Schafer said no additional investigation is planned.

Rob Jennings may be reached at rjennings@njadvancemedia.com. Follow him on Twitter @RobJenningsNJ. Find NJ.com on Facebook