Nathan John Luna was pronounced dead Thursday at Holland Hospital about two hours after the incident. Authorities believe he broke his neck.
Luna was on a boat with three children in about 3 feet of water when he either dove or jumped. The 34-year-old Holland man was pulled toward shore by his daughter.
He was an assistant principal at L. C. Mohr High School in South Haven and played football in his younger days at Saginaw Valley State University. His nickname was "gentle giant."