Lifeguards rescued a 23-year-old woman Friday after she was hit in the head by a surfboard while surfing off Waikiki.

A lifeguard saw the incident while patrolling the water on a surfboard and went to the woman about 4:20 p.m., a lifeguard dispatcher said.

The woman was face down and unconscious in the water. She regained consciousness after the lifeguard pulled her onto his board. The lifeguard brought her to the beach fronting Moana Surfrider hotel, where lifeguards gave her oxygen and stabilized her.

Paramedics took the woman to the hospital in serious condition, an Emergency Medical Services supervisor said.