Tobermory is about 10 hours away from Ottawa.
We went there for a long week end, essentially to dive. The place is famous for wreck diving. Most of the shipwrecks are natural, some have been sunk for tourists only. The water was around 5 degrees... And everybody brought their own drysuit, but us!
On top of the diving, Tobermory is a nice little place, with places to hike, like the cliffs at Cyprus Lake, or the beach at Dorcas Bay, where the water is surprisingly warm on the shore compared to the rest of Lake Huron.