Sorry for the Cambridge jargon...  the May Bumps are a series of
races to culminate the rowing season in Cambridge.  The river's
not wide enough for side-by-side racing, so the 30-some-odd colleges
that make up the university basically play a big game of water tag.
Which goes on for 4 days! And some keep score over *years*. My college
is Clare Hall (incidentally, Dan Estes's college too!)

A more thorough explanation of the May Bumps, with pictures, can be found here: http://www.firstandthird.org/frames/rowing/bumpsintro.shtml