The 65-year-old victim was bitten Thursday night about 20 miles off the Charleston coast, Petty Officer 3rd Class Vincent Moreno said via local news outlet WCSC.
Police then directed the boat to head into the Charleston Harbor to meet EMS at Tad Street next to Coast Guard Station Charleston.
The man was out at sea on a 28-foot boat.
A passenger on the boat with the man applied a tourniquet to stop the bleeding until Coast Guardsmen arrived.
Charleston Harbor Marine Police responded to the boat and assessed the man’s injuries, determining that the bleeding had stopped, Moreno said.
EMS transported the man to the Medical University of South Carolina for further treatment. His condition remains unclear as of Friday night.