the hydrodynamics on a sub is different to a surface ship
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submerged cruising is 5 times more energy efficient due to the absence of wave resistance - if your ship creates waves - waves are energy that comes directly from your engine and is lost for propulsion - this is why mother nature abandoned the concept of "animals swimming long distances on the surface" - all animals as soon as they evolve to be aquatic - go below the surface for good reasons. Even whales swim below the surface although they still have surface dependent respiration - technically speaking they cruise in "snorkel mode"
-- Edited by admin on Friday 18th of January 2013 02:27:02 PM
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