Family and friends identify him as 48-year-old Jeremy Niesen, and they told ABC13 Niesen has an intellectual disability.
"He's my life. We were planning to get married this year," said Niesen's fiancé Shirley Espiritu.
Espiritu last saw Niesen late Saturday morning, when he left home to go out on his long-time friend Robert Ray's boat.
"(Niesen) and Robert Ray said they were going to go try the boat out, because (Ray) just bought a brand new motor for the boat, and they wanted to ride around," Espiritu said.
Espiritu called Niesen around 1:30 p.m.
Niesen told Espiritu he and his friend were about to get ready to bring it in.
But around 2 p.m., the boat collided with another boat on Lake Houston near Ponderosa Marina in Huffman.
Ray was transported to the hospital.
"He's got several broken ribs, bruised up pretty bad. He has neck injuries and a possible head injury," said Ray's brother Adrian Ray.
The Houston police dive team went into the water searching for Niesen shortly after the accident, and continued their search well into Saturday night.
"If this is it, it's a huge loss for a small group of people. But we hope he comes home," said Niesen's boss and friend Troy Shuford.
Shuford and all of his loved ones wonder if he got to shore after the crash and is somewhere wandering around Huffman.
Espiritu said she won't believe Niesen's gone until she sees his body.
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