[motto]

The presence of the submarines was perhaps not quite as serendipitous as it may appear. Subs were stationed along the route the bombers were traveling on the way back to their bases for just such an eventuality as this and the aircraft navigators would have known their locations and radio call signs. The reason for two subs would be so as one could remain on station while the other went looking if necessary. Search and rescue aircraft were also on standby on the ground and some even airborne.
Quite apart from any humanitarian considerations the highly trained bomber crews represented a significant investment.

David