It happened just before 8 p.m. near the corner of North Delaware Avenue and Orthodox Street in Bridesburg, authorities said.
The remains were found in the water by a passing ship and reported to the US Coast Guard, police said. A police boat recovered the body and turned it over to the Medical Examiner's Office for identification, according to PPD.
The man is described as being white and between 40 and 50 years old. Police said he was likely "decomposing for several days."
Click here to follow Daily Voice Bristol and receive free news updates.