Usually a few times over the summer. I'm taking part in a C3 cruise around Georgian Bay on May 31-June 2. We will be meeting up near you and heading to Tobermory for the Friday night, already have accomodation booked, and then catching the Chechimun to Manitoulin Island on the Saturday morning. Ferry is also booked, as is accomodation in Parry Sound for the Saturday night. So far there are 6 C3's booked to go, if you're interested, let me know.
I usually make it to the Wasaga Corvette Weekend on the Saturday and take part in the cruise. I work 4 10's and am done on Friday mornings; so over the summer, if the weather is nice I'm bound to be heading towards Wasaga for the day......so Collingwood wouldn't be out of the question.