Iteration 1:  Quick and Dirty -- Humpback's are good at going long ways efficiently during their migrations.  Maybe use that as a starting point.  Downloaded some 3d models of whales, concept to do an area rule and make hull shape similar.  Looked for research papers on hydrodynamics of cetaceans.  

• Hydrodynamics of Dolphins
  • An indicator of streamlining is fineness ratio (max dia/length)  4.5 gives least drag and surface area for maximum volume, although only 10% drag increase in FR of 3 to 7.  
  • Dolphin body form similar to 2d airfoil NACA 66-018.  Killer whale NACA 66-026.  Both laminar flow airfoils

Orca Images