[aerohead]

One of my books about sharks presented the following data:
These marine creatures are presented according to their body length,divided by there maximum body width as measured from above (plan-view)
*Bluefin tuna--------------------------------------------------- 3.571:1
*Swordfish----------------------------------------------------- 4.166:1
*White shark (JAWS) ------------------------------------------- 3.846:1
*Cod ----------------------------------------------------------- 6.25:1
*Mackerel ------------------------------------------------------ 7.142:1
*Eel ------------------------------------------------------------ 20.0:1
*Blue whale -----------------------------------------------------4.76:1
*Bottle-nosed dolphin --------------------------------------------4.00:1
*Emperor penguin ------------------------------------------------3.846:1
*Harp seal ------------------------------------------------------ 4.166:1
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According to Sighard Hoerner,a symmetrical wing section or strut would have a drag minimum at L/W= 4.00.
You can see from the list that six of the listed swimmers are near this drag minimum.