Re: What's a sailor to do in London?
Forgot to mention - since you asked - Foyles Bookstore (Charing Cross, as I recall) used to be the biggest bookstore in the world, with around 30 miles of shelving; so if you want to look for a book, that's a good place to go.
Also, the Thames has *really* cleaned up. When I was a lad, if you fell in the Thames, it was standard to get your stomach pumped. Last summer when I was there I saw a guy *fishing* off The Embankment. I was stunned.
Also - HMS Belfast - just over from Tower Bridge - is interesting. Many people also like the London Dungeons. Although I have never been there, apparently the massive Victorian engines which raise and lower Tower Bridge are occasionally open to the public....