Four of us also did the Gananoque Boat Tour 5 hour trip, so this gives us a good comparison of the two popular excursions of the area. If you have the time, you should do both. If you have to pick one (and are athletically inclined), I would recommend the kayaking trip. The boat tour has the castle part, and you see many of the islands. However, after a while, there isn't much exciting going on. With the kayaking trip, you will see fewer islands, but will have a more "up close" experience.
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