Compare replenishment systems at the same date

A traditional claim holds that the United States Navy uniquely mastered Pacific logistics while the Royal Navy's bases discouraged replenishment at sea. American geography encouraged large fast oilers and rapid technical improvement, but much of this capacity entered service in the late 1930s and early 1940s. British techniques look inefficient against the American standard of 1944, not necessarily against what either navy could do in 1939 or 1941. Comparisons must hold the date constant before turning wartime improvement into a verdict on interwar competence.