Maryland Natural Resources Police spokeswoman Candy Thomson says the man's name was Salvador Amilcay Santos. He lived in New Carrollton.
Santos was one of five people aboard a boat that began taking on water and capsized around 3 a.m. Sunday at the mouth of Fishing Creek in Chesapeake Beach. None of the other four was injured.
A bystander pulled all five people from the water and began performing CPR on Santos. Firefighters took him to a hospital, where he was pronounced dead.
He was the second person to die this year in a boating accident in Maryland waters.