I visited USS Silversides in late September. It's very nice. The location is rather remote, but there is plenty of signage leading to the spot, and it's pleasant enough there. It's near a fine beach, so I imagine they get good crowds in the summer. I saw evidence of excellent public outreach and programs for the community. The gift shop is well-stocked, too. :-)
When I arrived for my visit, there was a chain across the entryway to the boat, and I feared they might be closed for tours. I went inside the museum building, saw they were open, paid my fee, and the folks there explained that the tour was self-guided and I should just unhook the chain and let myself on-board. Ok... Entry near the forward hatch is unique for the submarines that I've seen. It's neither the main hatch, as on Cod, nor the more typical re-built torpedo loading hatch. You descend below the bow superstructure through a small set of stairs, step onto the pressure hull and then walk around about ten feet to a hatch that has been cut into the hull on the port side right at the back of the forward torpedo room. There's no sign explaining this, and when I first made my way down, I saw the closed hatch in front of me and wondered if I was expected to open that myself to go below! I'll attach a photo of the view from here. By the way, is there a name for this large open area in the bow between the pressure hull and superstructure?
The interior of the sub is in very good shape. I had the sub all to myself for the duration of my half-hour exploration and had plenty of time to experience the "ambience" of the old vessel. The exterior seems to be in good condition, too. The paint looks good, and the presentation is good. There's a lot of algae growing below the waterline but I imagine it's relatively harmless, and it keeps a small flock of ducks happy picking away at it for their breakfast.
-FER
PS: So... there are museum subs in Muskegon and Muskogee. I smell a rat... a muskrat.