A humpback whale collision with a research boat off the coast of Maui knocked a woman to the deck and sent her to the hospital.

The vessel Hokulani was near a pod of whales Friday when one whale went under the boat and surfaced on the starboard side, said Maui Police Capt. Charles Hirata.

The whale's fin came down and crushed a thin railing on the 26-foot twin-outboard catamaran, he said. The 61-year-old woman from Bremerton, Wash., was standing in the bow of the boat and hit her head when she fell.

She has not been identified, and police say she was conscious and alert when the ambulance arrived.

"They actually have a video of it," Hirata said. "You can see a person standing there and the flipper hitting the side of the boat."

The research boat for the Center for Whale Studies had the required permits to venture near the endangered and federally protected whales, said Naomi McIntosh, superintendent for the Hawaiian Islands Humpback Whales National Marine Sanctuary.

The incident will be investigated by the National Oceanic and Atmospheric Administration, McIntosh said.

This was the third strike involving a whale and a vessel this season, all of which occurred in Maui waters, McIntosh said. No injuries were reported in the other collisions.

"This is a perfect reminder to boaters out there: This is the peak of the whale season, and weather conditions make it extremely difficult to see whales at the surface of the water. And when they come up to breathe, their mist is carried away quickly by the wind," McIntosh said.

The Center for Whale Studies had another unusual incident in Maui waters in April 2003, when a marlin speared Mark Ferrari, the nonprofit whale center's co-director, through the right shoulder.

Friday's collision also involved the Ferraris, said Randy Awo, Maui branch chief for the Conservation and Resources Enforcement Division of the Department of Land and Natural Resources.

Efforts by The Maui News to reach the Ferraris on Friday were unsuccessful.