An elderly boater died in a horrific, freak accident as he fished in Brooklyn’s Gravesend Bay yesterday, authorities said.

Florijam Kasumovic, 74, of Passaic, NJ, drowned after his leg apparently got stuck in the railing of his small pleasure craft and he fell overboard. His head was partially submerged under water as he dangled from the side of the vessel, police sources said.

Harbor police towed the white fishing boat, with the body still aboard, to a Sanitation Department pier near Shore Parkway to further investigate.