A South Jersey man drowned in the Delaware River while swimming off of a beach at a national park in Pennsylvania, officials said Saturday. About four hours after going missing, divers retrieved the body of 24-year-old Jeysson Ariel Osorio-Reyes, of Jackson Township in Ocean County, off Milford Beach at the Delaware Water, National Park Service officials said. Osorio-Reyes, according to a witness, was seen swimming around 3:15 p.m. about 75 yards from the shoreline in Pennsylvania before vanishing underway. His body was found around 7 p.m. Saturday. The National Park Service was aided in the s…