What is London River?
1.
The
This is a nautical or marine term, dating back many centuries, to the time when London was (one of) the main ports of England - see also
Still in use in the 1980's, and probably beyond.
After over a year away on a British ship, seamen of all ranks would often get the 'Channels' as they passed between England and France, prior to ascending the London River and berthing in The Pool of London - and then paying off!
See