German airline Lufthansa subsequently used dedicated catapult ships , , "Ostmark" and "Friesenland" to launch larger Dornier Do J "Wal" (whale), Dornier Do 18 and Dornier Do 26 flying boats on the South Atlantic airmail service from Stuttgart, Germany to Natal, Brazil. On route proving flights in 1933, and a scheduled service beginning in February 1934, "Wals" flew the trans-ocean stage of the route, between Bathurst, the Gambia in West Africa and Fernando de Noronha, an island group off South America. At first, there was a refueling stop in mid-ocean. The flying boat would land on the open sea, be winched aboard by a crane, refueled, and then launched by catapult back into the air. However, landing on the big ocean swells tended to damage the hull of the flying boats. From September 1934, "Lufthansa" had a support ship at each end of the trans-ocean stage, providing radio navigation signals and catapult launchings after carrying aircraft out to sea overnight. From April 1935 the "Wals" were launched directly offshore, and flew the entire distance across the ocean. This was possible as the flying boats could carry more fuel when they did not have to take off from the water under their own power, and cut the time it took for mail to get from Germany to Brazil from four days down to three.