A shark believed to be a great white killed a 66-year-old swimmer with a single, giant bite across both legs Friday as the man trained with a group of triathletes, authorities and witnesses said.
Dave Martin, a retired veterinarian from Solana Beach, was attacked at San Diego County's Tide Beach around 7 a.m., authorities and family friend Rob Hill said.

Martin was taken to a lifeguard station for emergency treatment but was pronounced dead at the scene, according to a statement on the Solana Beach city Web site. His injuries crossed both thighs, San Diego County sheriff's Sgt. Randy Webb said in a news release.

Scripps Institution of Oceanography shark expert Richard Rosenblatt says the shark was probably a great white between 12 and 17 feet long.

"It looks like the shark came up, bit him, and swam away," said Dismas Abelman, the Solana Beach deputy fire chief.

There was a single bite across both of Martin's legs, Abelman said.

The attack took place about 150 yards offshore. Several swimmers wearing wetsuits were in a group when the shark attacked, lifeguard Craig Miller said. Two swimmers were about 20 yards ahead of the man when they heard him scream for help. They turned around and dragged him back to shore.

Swimmers were ordered out of the water for a 17-mile stretch around the attack site and county authorities sent up helicopters to scan the waters for the shark. Eight miles of beach were closed.
"The shark is still in the area. We're sure of that," Mayor Joe Kellejian said.

Hill, a member of the Triathlon Club of San Diego, said he was running on the beach while about nine other members were in the water when the attack took place.

"They saw him come up out of the water, scream 'shark,' flail his arms and go back under," Hill said. "The flesh was just hanging," and Martin may have bled to death before he left the water, Hill said.

A witness, Ira Opper, described the victim as "burly and athletic." He said the man was wearing a black wetsuit that was shredded on both legs.

Club members had been meeting at the beach for at least six years and never had seen a shark, Hill said.

However, Hill said he saw a seal or sea lion on the beach earlier this week. Miller said a seal pup was found on the beach Friday morning before the attack and was taken to a marine animal rescue center.

The shark may have confused the wet-suited swimmers with his prey, Hill said.

Rosenblatt, the shark expert, said white sharks travel through the area, and the way the man was attacked and the "massive" but clean wounds "sounds like what a white shark would do."

White sharks hunt along the bottom, look for seal silhouettes above and then rise to attack, he said.
"A human swimmer is not too unlike a seal," he said.

Shark attacks are extremely rare. There were 71 confirmed unprovoked cases worldwide last year, up from 63 in 2006, according to the University of Florida. Only one 2007 attack, in the South Pacific, was fatal.

The last fatal shark attack in California, according to data from the state Department of Fish and Game, took place in 2004, when a man skin diving for abalone was attacked by a great white shark off the coast of Mendocino County. On Aug. 19, 2003, a great white killed a woman who was swimming at Avila Beach in San Luis Obispo County on the central California coast.

Solana Beach is 14 miles northwest of San Diego.