Distributing submarines across home and imperial ports

The early submarine program now produces boats at Belfast, Brisbane, Cork, Liverpool, Melbourne, Plymouth, Perth, Bournemouth, Scapa Flow, Sunderland, and other ports. Dispersal gives many bases a local undersea threat instead of concentrating the entire force in one theater. Enough submarines in home ports make an enemy attack much more complicated. The result follows the geographic logic of the earlier construction plan: numerous short-range craft can impose sea-denial risk across a distributed network even though they cannot replace the battle fleet.