London Colleges League includes other clubs outside London, such as University of Reading.
In the Hampshire League Reading (Berkshire) and Bournemouth (Dorset) compete and have hosted races. Chichester (Sussex)compete and have hosted races at Goodwood (also in Sussex). Other clubs outside of Hampshire which compete in the league include Poole (Dorset), Wimborne (Dorset), Salisbury (Wiltshire), Camberley (Surrey) and Farnham (of Aldershot, Farnham & District fame) is also Surrey - perhaps that doesn't count though if the club is fully based in Hampshire. People sometimes compete from the Channel Islands (I've seen Guernsey and Isle of Wight in the results).
Arguably many of the Surrey clubs are London (Belgrave, Thames Hare and Houses, Ranelagh, Croydon, all Clapham and Wimbledon clubs are all in Greater London. Should the Surrey League be restricted to Epsom, Dorking, Reigate and a few others?