I haven't actually camped at Goose Island, so I can't comment on that. However, we did recently rent canoes there. The rentals are cheap- $7.50/hour, and they even prorate it by the exact number of minutes you are out! You have to take the canoes out from their dock (can't go to any of the other boat docks), but even if you don't canoe the whole canoe trail, it doesn't matter- the current there in the backwaters is negligible, so going or coming is pretty easy. You mainly have to watch out for the wind direction. They have a low number of canoes (maybe 8) and don't take reservations for canoeing, so that may be a problem on a summer weekend, but other times it should be fine. You can also bring your own canoe/kayak and put in the water here for free.