Over wonder why the Red October was so damn slow? It is obvious, water is heavy and it takes a lot to plow through it (compared to air, at least). The Pentagon has developed the Underwater Express, a submarine capable of going 127 mph (compared to modern sub speeds of 29 mph, by encasing the entire sub in a bubble. Bubbles can move through the water quicker and therefore cause no drag on the actual submarine. Now if only we could get in a war with a country with a large body of water. Iraq is just too dry.

Underwater Express Program [Via SCI FI]