According to investigators, it happened just before 1 a.m. along the shoreline of the Diamondhead neighborhood.
Crews arrived to find a boat with three people had hit a bulkhead.
A 54-year-old man identified as Roy Taylor was thrown from the boat.
A family who lives nearby tried to perform CPR, but weren't able to save him, which they say was devastating.
"We just ask that everyone take all precautions this week and be responsible. Perhaps this accident could have been avoided," said resident Roy Henderson.
The cause of the crash is still under investigation.
The man operating the boat and a teenage girl on board suffered minor injuries.
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