LIVERMORE -- Dive crews embarked on a second-day search for a Mountain House man who disappeared below the surface of Livermore's Lake Del Valle while kayaking with his sister on Sunday.
Crews thinned on day two to a small group of East Bay Regional Parks District officers, two police dogs and three divers equipped to scan the bottom of the lake using sonar, East Bay Regional Parks Police Sgt. Chuck Torres said.
The search resumed at 8 a.m. Monday after a three-hour effort Sunday afternoon that included teams in helicopters and boats, on-duty lifeguards and a dive team with the Alameda County Sheriff's Office, that wrapped up without a trace of the missing kayaker.
The 30-year-old man, who has not been identified, reportedly stopped paddling the two-person kayak he rented with his sister about 2:30 p.m., about 100 yards from the west shore of the lake, Torres said. It was at that time the man decided he wanted to go for a swim and removed his life vest before plunging into the water.
The man swam all the way to the west shore and was on his way back when he yelled to his sister in the kayak to throw him his life vest, Torres said. The woman was scrambling to get the man his life preserver when she saw him sink beneath the surface.
It wasn't clear why the man called out for the life preserver, Torres said, but his ability to swim from the kayak to the west shore without any trouble indicated he was a fairly proficient swimmer.
Fire crews responded to the regional park at 7000 Del Valle Road about 2:30 p.m., and, along with on-duty lifeguards, cleared the water of visitors on both sides of the lake. While there were other people present on the other side of the lake, authorities believe the woman was the only person who saw the man go under.