I planned a trip a few years ago and never took it.

If you're driving, consider the overnight ferry from Portland, ME to Yarmouth, NS, then a week or ten days to do a counterclockwise loop, including a day or two in Haifax and be sure to include Cape Breton Highlands National Park. You should also try to include Lunenburg, a UNSECO World Heritage site.

On my itinerary I would have ridden the CAT high-speed catamaran ferry from Yarmouth to Bar Harbor, Maine.