A boater was transported to a Suffolk hospital with a head injury Sunday night after his boat ran aground just south of Tanner Park in Copiague, officials said.
U.S. Coast Guard officials said they responded to the scene of the accident involving two boats shortly before 9 p.m.
"It appears one boat was following another boat at a high rate of speed, south of Tanner Park in the Lindenhurst area, when the one boat that was following ran aground," said Command Duty Officer Mark Averill, of the U.S. Coast Guard Long Island Sound Sector.
Averill said the men were believed to be friends.
The injured boater was transported to Good Samaritan Hospital with nonlife threatening injuries, Averill said. The other boater was not injured.
Authorities are investigating to determine if either boater was driving under the influence, Averill said.