HANALEI, Kaua'i — An estimated 14-foot tiger shark chomped the end off a local surfer's board Monday afternoon in Hanalei Bay, witnesses said.

North Shore resident Leslie McTaggart, who was nearby when Jim Rowlinson was surfing at the point, said the water "boiled" as the shark swam by and took a bite out of Rowlinson's blue longboard about 4 p.m.

McTaggart yelled for help, assuming at the time that the shark had pulled Rowlinson underwater. As it turns out, Rowlinson apparently dove off his board to undo the leash fastened around his ankle.

"The shark was spitting pieces of the board out right under me," McTaggart said, noting how she saw its tail thrashing in the water. "The guy could've died."

Based on the teeth marks embedded in the board, marine biologist Terry Lilley of Save Our Seas said the shark was likely 14 feet long. He estimated this because the base of the tooth measured 1.25 inches.

Lilley said the shark was likely chasing after a turtle when it mistakenly bit the surfboard. He said Rowlinson noted he saw a "yellow flash," which could have been the underside of a turtle, just before the shark bit his board.

"The problem is we all look like turtles," McTaggart said of a shark's view of surfers sitting on their boards in the water.

The Ocean Safety Bureau on Kaua'i said no sharks were seen in the area yesterday.