If that's the one by/on King George V dock, I had a small run-in with the police round there a couple of years ago. I was working on the Golden Hind (now safely back in Southwark) across the river on the Woolwich side, and one afternoon we took the lifeboat out for a spin, to check it was OK and to get used to using a motor considerably too big for the boat it was on. All of a sudden we got surrounded by heavily armed river police types. When they found out which ship we were on, though, they were suitably impressed and later on a whole gang of them turned up for a look round and a sneaky cup of tea whilst on duty. Tom