There are two cities in Connecticut: New London and Groton, that served a similar purpose. I believe they built submarines in Groton. New London is served by Amtrak passenger rail. They both have an impressive maritime history but are somewhat economically depressed. I have never really felt the need to visit either, but I suspect they're both interesting places in their own way.
I really enjoyed Liverpool, but it struck me as a beautiful place at the turn of the last century, with shipping and railroad money as well as overflow capital from nearby textile centers. The Albert Docks and the Maritime museum were highlights, but there were beautiful auditoria and pubs that reflected the former prosperity as well as the magnificent cathedral. There's a branch of the Tate Modern (or at least there was) that had a minimalist sculpture exhibit. But that was a million years ago. I don't know if its situation has improved or declined since then. I expect there's plenty of interesting historic buildings in both Portsmouth and Gosport. If we ever get past this pandemic, we'd like to travel more in the UK, but right now we are still waiting to get a vaccine.