SUBMARINES AS SURFACE BOATS
Despite their name, submarines are really surface boats. Only when necessity demands are they submerged. During the war even the U-boats did 90 per cent of their sailing on the surface. Origially submarines were built primarily for submerged travel and consequently they were given the form of a fish or of a fat cigar, but such a shape was not adapted for surface sailing. Water piled up on the nose of the boat and tended to bear her down. To overcome this, submarines are now shaped more like a boat with a bow high enough to part the waves without burrowing into them.