tri suit or wet suit

I'm not sure if you are asking if you should race a half with a wetsuit or if you should train with a wetsuit. If you are racing with a wetsuit I would certainly train with one as much as possible. I have not done Peterborough, but I assume that water temperatures that time of year are reasonably warm, so that is not an issue. I would estimate that a wetsuit saves me 3-4 minutes on a 2 km swim, and saves a little energy. Trisport had wetsuit strippers at Muskoka, so if they have them at Peterborough as well that would be another reason to wear one as you don't waste any time removing them.