Some of the main
marinas in London are... Poplar
dock, lime house, st. Katherine
Dock, South Dock. That's all I can think of for now.
If you want to
live aboard, poplar and lime house are both about £10,000 for a year and south dock is cheaper but has a 2 year waiting list. It also depends on how flashy your
boat is - I've encountered a lot of yacht snobbery in London.
Marinas don't want grubby, 'well loved' boats spoiling the view!
Or you could keep her in Portsmouth. We have kept our
family boats in Haslar marina (1hr 40 train from waterloo) or anywhere in
Southampton.
Hope this helps your decision making!