SEATTLE -- A scuba diver died after being pulled from the water near Alki in West Seattle on Monday.

A dive instructor was underwater with a group of students when they noticed another diver unconscious. The man was not part of the instructor's class.

The group pulled the man to the surface south of Seacrest Marina about 11:30 a.m. and called 911.

Seattle Fire Department Lieutenant Harold Webb said medics performed CPR for more than 20 minutes but the man died at the scene.

The dive instructor said he and a student found the man tangled in a buoy chain.

"It was wrapped around his regulator," the instructor said.

It was not known how long the man had been underwater, and his name has not been released.