The North Atlantic is increasingly developing into the main trade route of the age. Shipping, the pioneer along this highway of commerce, in the past decade has been joined by air traffic displaying a striking growth rate. Not only is the number of aircraft simultaneously plying the Atlantic routes constantly on the increase, but also the volume of passengers and freight transported on each flight. The question, whether such flow of traffic in the air and on water could be dealt with in future with the safety to which it is entitled, has led to world-wide discussions over the past few years concerning the necessity for an air traffic surveillance system for the North Atlantic area. A further question, whether one should not include also sea traffic in such a system suggested itself. The initiative for holding such discussions naturally proceeded less from air and shipping undertakings, but rather from those committees who are entrusted in supervising the safety in the conduct of man and merchandise.