 Land-based German bombers used for search duties proved inadequate in range, so bomber air bases were constructed along the coast to facilitate an air net over the Baltic and North seas.Following this, the "Luftwaffe" determined to procure a purpose-built air-sea rescue seaplane, choosing the Heinkel He 59, a twin-engine biplane with pontoons.A total of 14 He 59s were sent to be fitted with first aid equipment, electrically heated sleeping bags, artificial respiration equipment, a floor hatch with a telescoping ladder to reach the water, a hoist, signaling devices, and lockers to hold all the gear.