An oil spill chased about 150 people from the lagoons of Ko Olina Resort yesterday, but did not appear to cause any significant injuries or environmental damage, officials said.

The oil from an unknown source, estimated to be about 500 gallons, spread a light 3-mile sheen in the water from Barbers Point to Kahe Point, said Coast Guard Lt. John Titchen. It was moving west last night, he said.

The Coast Guard was monitoring the spill with a helicopter, C-130 plane and a 47-foot boat last night. Using money from a national oil spill recovery fund, it also hired a local company, Pacific Environmental Corp., to lead cleanup efforts.

The sheen came ashore at three of the lagoons at Ko Olina about 11 a.m., causing some people in the water to report a strong diesel smell in the air and a light touch of oil on their skin, officials said. Several people in Nanakuli also reported encountering the oil last night, he said.

Titchen said the sheen appeared similar to marine diesel fuel, which evaporates fairly quickly.

At least two other spills of a similar size and substance have been reported in Hawai'i waters in the past year, he said.

No one was seriously injured, said Honolulu Fire Department Capt. Terry Seelig.

Security personnel at Ko Olina walked the beaches yesterday advising people to stay out of the water. By late afternoon the beachfront lagoons, which normally have hundreds of people on a sunny Saturday afternoon, were all but deserted.

"The good news is there's plenty of parking, and we got a cabana for shade," said Yvonne Walker of Salt Lake, who came to the beach with family members, including 5-month-old granddaughter, Milanna, who was making her first visit to any beach.

"A lot of people went home, but we're just not going in the water," said Walker's daughter, Amber. "When we get hot, we go use the showers."

The Coast Guard was working last night to determine the source of the spill, Titchen said. The state Health Department also was investigating.

"It's mostly offshore at this point, but there is some shoreline impact," said Coast Guard Petty Officer 1st Class Aaron Cameron. "We'll be out here working to ensure there is as little impact to the environment as possible."