These maritime tensions exploded, literally, in 1807 off the shore of Chesapeake Bay. A British naval squadron was watching the area for French ships when several British sailors managed to desert and promptly to enlist in the American navy. The captain of the American 38-gun frigate Chesapeake knew that he had deserters on board when HMS Leopard tried to board and search his ship. When the Chesapeake refused to heave to, the 50-gun Leopard opened fire, killing three and injuring 18 of the crew. The British boarded and seized four men. This "Chesapeake Affair" outraged even temperate Americans. The actions of the British ship HMS Guerriere on 1 May 1811 in impressing an American sailor from a coastal vessel caused further tension.