Keyport Undersea Warfare Museum, Washington State, USA

The best Navy-oriented undersea museum I've seen.  Yes, that's pretty specific praise but this is really worth visiting if you're the type of person that enjoys most of the Sub-Log.com articles.  The focus is on undersea warfare but there are displays of deep sea diving rigs along with the big rack of torpedoes and mockup of the USS Greenling (SSN 614) control room.

     Trieste II (#2)

Location: Keyport, WA, USA 

Highlights: Trieste II out in the parking lot, torpedo collection

Official Website: http://keyportmuseum.cnrnw.navy.mil/