LIVERMORE (KPIX 5) — Search and rescue teams were attempting throughout the night to locate a man who went overboard while boating with friends at Lake Del Valle on Tuesday afternoon.

East Bay Regional Park District police said they were still in search mode late Tuesday evening, but as the hours go by and the night sky gets darker, it gets more difficult for dive teams to see.

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“We have to make a constant assessment of the rescuers’ safety. We have to keep our people safe to make sure we can help the people we’re trying to help,” said Lt. Terrence Cotcher of the EBRPD police.

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Cotcher said the young man was with friends on a small fishing boat enjoying the hot weather. Cotcher said Tuesday’s accident was the second of its kind at the same spot–another person fell out of a boat on Saturday with no life jacket on. The victim was recovered from 44 feet of water.

With a long summer ahead, EBRPD officials are urging people to be careful.

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“We’re going to be advocating for water safety all the time. That’s our message,” said Pete DeQuincy, the Aquatics Manager for Del Valle Regional Park.