[peterloo]

In early war, (must be in the right time in 1939~1940), scapa flow, firth of forth, liverpool (never, never, too many minefields+patrols),...

Later war, NEVER. Capital ships NEVER dock at ports, but goes with task force. You may be able to inflitrate a base with a Light cruiser and several landing ships, troop transports, and other stuffs with Harbour Traffic v1.47 mod which I used before GWX.

WARNING, ALTHOUGH ALL OF THE PREYS ARE JUICY (I prefer landing ships first since they must go down with 2 fish, with appox. 300 renown falls on my hand), NEVER SURFACE, since TROOP TRANSPORTS OWNS 6 GUNS and a lot of MGs. The Cruiser, of cause the more. I once died due to the greedy mind

You can never sunk all of them, as you don't own enough fish (even XXI is not adequate if u use duds and the weather is no good)