A surfer was in critical condition Thursday after injuring his head at Pipeline on the North Shore.

Beachgoers found the man underwater, still attached to his surfboard, after noticing a board adrift and checking to see whether anyone needed help, said Honolulu fire Capt. Terry Seelig.

An Ocean Safety dispatcher said lifeguards used a personal watercraft to bring the unresponsive man onto shore at Ehukai Beach Park at about 4:50 p.m. Lifeguards performed cardiopulmonary resuscitation and revived the man, the dispatcher said.

Paramedic dispatch reports said the man had an injury to the back of his head.

Local surfer Kaleihao Crabbe, 31, said the man was surfing when he cut Crabbe off on a large wave and went over the falls.

"The waves just pounded him," Crabbe said. He said the man appeared to lack experience for the large surf because he was using the wrong type of board and because of his paddling style.

"I feel partially responsible for this," Crabbe said afterward by phone, saying he considered telling the man to get out of the water for his own safety but didn’t want to offend him.

Ocean Safety said the surf was about 8 to 10 feet high at Pipeline, the break at Ehukai Beach Park, at about 2 p.m. Thursday.