These Liberators operated from both sides of the Atlantic with the Royal Canadian Air Force and the Army Air Forces Antisubmarine Command and later, the US Navy conducting patrols along all three American coasts and the Canal Zone. The RAF and later American patrols ranged from the east, based in Northern Ireland, Scotland, Iceland and beginning in mid-1943 from the Azores. This role was dangerous, especially after many U-boats were armed with extra anti-aircraft guns, some adopting the policy of staying on the surface to fight, rather than submerging and risking being sunk by aerial weapons such as rockets, gunfire, torpedoes and depth charges from the bombers. American Liberators flew from Nova Scotia, Greenland, the Azores, Bermuda, the Bahamas, Puerto Rico, Cuba, Panama, Trinidad, Ascension Island and from wherever else they could fly far out over the Atlantic.