The kids and I went to visit the USS Slater yesterday. The USS Slater is a Destroyer Escort from World War II.Admission includes a 7 minute video about destroyer escorts and a 1 hour guided tour of the USS Slater. The older kids had a really nice time.
Strollers are not allowed on the boat, so I would not recommend this for families with a few little ones. There was lots of climbing up and down ladders to get to different sections of the boat. I missed out on half the tour, sitting out with my baby and toddler. There was no way I could maneuver the steps with a baby on my hip (you need both hands to hold the railings.)
The gift shop was very reasonably priced and had a nice selection for the kids to chose from.