UPDATED: 09/04/16, 10:48PM

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GRAND PRAIRIE (CBSDFW.COM) – The search for a missing boater will continue at Joe Pool Lake Monday morning. First responders have been looking for the man since just before four o’clock Sunday afternoon when family members say he jumped in the water and never resurfaced.

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Police and fire boats focused on an area near the dam on Joe Pool Lake where witnesses said they last saw the man.

Game wardens said the 57-year-old was on his pontoon boat with several family members when he jumped into the water without a life jacket. The family had been on the lake for a few hours.

Firefighters got the call around 3:45pm and zeroed in on the man’s last known location, dropped buoys and began their search pattern.

Grand Prairie Assistant Fire Chief Bill Murphy said the man likely jumped into the water just to cool off, but he urged anyone who jumps from their boat into open water to always wear a life jacket.

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“People think they can just jump in and cool off, but this happens every year, so jump in with your life jacket on to cool off. You just never know. We don’t know what happens to these people when they go under. A lot of times we’re told they’re strong swimmers, so we don’t know what happens whether they cramp up, what happens,” Murphy said.

Divers stayed on the water well after dark, but eventually had to suspend their search.

Murphy said the lake covers areas with standing structures and barbed wire causing entanglement risks making it unsafe for divers at night.

A game warden said they are using GPS information from family members’ phones to help narrow the search area.

Divers will be able to follow up on any SONAR readings Monday morning.

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