We stayed at Seawall two nights because Blackwoods was full. Seawayy is about 45 minutes from Bar Harbor. There is a nice short walk to the ocean, and rocky beach. There is a free bus shuttle that stops at the campground. Very good to use to avoid having to park when going to Bar Harbor. Bathrooms were clean. No showers, but a few local businesses do sell showers.
I loved my 5 days here. There's a great trail behind the group sites for solitary walks, and the picnic area across from the entrance offers ocean time. Just gorgeous. Sites are private, large, level, and the bathrooms are centrally located and clean. One negative: no shower, anywhere, and the private options outside the park are filthy. Visited in June, 2018.
Max length 35'; height 11' 8"