[gone-ot]

The HK-1 (Hughes-Kaiser) was intended to transport troops & supplies ABOVE the Atlantic ocean, where the German submarines could not attack so easily as they did surface convoy ships. The goal was "above/out" of the water, but not so high altitude as to need oxygen masks for the troops. And, the lower the plane was to the water, the more the curvature of the ocean & earth blocked "line-of-sight" visual tracking from submarines on the surface...called "nap-of-the-earth" flying these days.