Choose one naval change for January 1937

The closing counterfactual limits the viewer to one navy and one intervention on 1 January 1937. Possible changes include ordering an individual ship, accelerating a class already under construction, restructuring training, or promoting a particular officer. Those constraints direct attention to a feasible early choice rather than an unlimited redesign of a country's armed forces. The prompt asks which intervention could most usefully widen a minor navy's later wartime options, and viewers supply their own answer.