I had the privilege of interviewing Olympic coxless four gold medalist Pete Reed (second from left, or No3) this evening for The Times. He's a giant in all senses (6ft 7in and the largest lung capacity on record, apparently).
As a qualified marine engineer and naval officer, Pete is one of the few athletes who has the intellectual equipment to analyse the equipment for his own sport. His dissertation for his BEng was an examination of the optimum setup for rowing. His conclusions were:
A) the longer the oars, the better,
B) the longer the stroke, the better.
These conclusions may seem obvious but they ain't. A longer stroke means a longer recovery, and longer oars mean more exertion by the rower, both of which may impact overall performance.
Reed wanted to look at the physiological impacts of varying stroke and oar length, but this got far too complex for a bachelor's degree. Apparently, professors of physiology are looking at this subject now. The results should be interesting.