Two scullers make their way up the Potomac during the Blue Plains Sprints a few years back. The Sprints is an annual regatta that pits T.C. Williams summer crew participants against each other in a series of races and marks the official end of the summer rowing season. Sign-up for the 2012 program is this Saturday, June 23, from 8-10 a.m. at the Dee Campbell Boathouse in Old Town.