One of the great things about the GPSTC is the 'Team' aspect. You need two sailors averages to score in a session. So the medium amd smaller guys get a looking, even on teams that have some of the bigger sailors, as support. Not just in the 2 sec and 5 x 10, but even more so in the other catagories which are more skills and strategy based, and sometimes not quite so reliant on outright top speed ability.
As a consequence, many of the Aussie teams have regular' jelly bean' getherers in the small/medium size range. As a further consequence of that, we get to see examples of the gear they use and how they set it up.
Also, when course are free, a big consequence and advantage of 'GPS', strategy become something smaller sailors can take advantage of as Kwibai very astutely points out.. If you put the thought in, and the effort into scouting and working out where the best spots are, or the best wind will be, even in a lake like Lake George, one can often find a way to keep up with the big guys, or at least keep them in sight.

I am sure many watcher of the GPSTC will quickly come up with a long list of small/medium size sailors, in all states, who fit this description.