We stayed here for three nights in the wilderness camping section for $75 which included tax and a gallon of drinking water each day. We found a great spot under the trees in a clearing with our firepit on the beach about 15 feet away from our tent. Firewood was $5 a bundle but you could easily get two fires out of it, three if you skimped, so it was perfect for our purposes (cooking). The showers were simple but clean, as was the rest of the main bathroom. The outhouse we used, near the wilderness camping, was clean but they did forget to restock toilet paper even though there were a few families in that area.
We could see the tides ebb and flow all day from our campsite, and the first night we were there we saw a minke whale go right up the western passage - it was amazing! We also saw porpoises and seals as well as seagulls and other seabirds, and a bald eagle that flew over our campsite and back a few times in search of fish for his breakfast. It was the best camping trip I've ever been on. The tidal whirlpool named "Old Sow" is a site to behold, and the beach and lighthouse on the campground are good for exploring. We even splashed in the ocean on the nice beach, but it's a bit cold (12 Celsius)!
It's a free ferry on and off the island if you come from Letete, south of St. George, NB. The campground is in a perfect location for daytripping around the island (I recommend a swim at Big Meadow Lake to cool off without all the salt or frigidity) and for sailing over to Maine or Campobello Island to daytrip around there. We saw porpoises and seals from the ferries (we took both), one of which was so close we could have touched it if we had been able to lean over the side - it was awesome!
We also went up the island to Seascape Kayak Tours and did a 3 hour tour out past Bean Island and saw more porpoises and seals (some only 10-20 feet from us!) as well as a bald eagle soaring through the air and perched atop a tall pine. It was an absolutely fantastic experience and we are now kayaker-wannabes for sure! We'll definitely go again and probably buy a kayak or two for ourselves soon.
I'd recommend this campground to anyone but please note: DEER ISLAND HAS NO LIQUOR STORE!!! hahaha... we didn't even think about it until it was too late but we were going to Campobello anyway and there is a store there. Ice can be had at a few stores on the island but most are only open til 6pm. All in all a great trip that I want to make an annual adventure.