A hypothetical 1920 program for Royal Navy bases

What Royal Navy infrastructure should Britain build after the First World War and before the Washington Naval Treaty?

Improve defenses and facilities at Scapa Flow and overseas bases, accelerate Singapore, strengthen dockyards, and retain existing repair capacity.

The scenario gives Britain an opportunity to authorize naval infrastructure after World War I and before the Washington Naval Treaty, with knowledge of the coming war. Dan first proposes proper defenses and better amenities at Scapa Flow, then improvements at Malta, Alexandria or Suez, and Singapore. Australian, Canadian, African, and Indian facilities are also considered, with Perth and Sydney receiving particular emphasis. A proposal to reuse guns from World War I monitors would strengthen Singapore and Hong Kong without depending on weapons that did not yet exist in 1920. Hong Kong is still expected to fall, but stronger defenses would make its capture more costly. Keeping Rosyth active is another proposed way to preserve useful capacity.