Following a question posed on the Masters Rowing Group on Facebook, about why boats are 'Tandem' rigged, I found a nice article published on the MIT Emerging Technology website, that seems to answer the question.
Originally published on MIT, November 20, 2009, a mathematician appears to have discovered why different arrangements of rowers in a racing eights enable the boat to be 'wiggle-free'.
They take their rowing seriously . . .