Yorktown and Illustrious fit different geostrategies

American and British treaty carriers answer different geographic problems. Yorktown's standard displacement was 19,800 long tons, favoring a large air group and Pacific maneuver with repair facilities available across an American support network, including plans for Hawaii. Illustrious used 23,000 long tons for armor, subdivision, and the ability to keep operating under land-based air attack in the Mediterranean or Far East. British planners expected damaged ships far from home yards to remain useful and repairable. The planned British approach through the South China Sea and East China Sea also offered less maneuvering room and more exposure to land-based aircraft than the American advance across the Pacific. Both designs are efficient when judged against the missions and deployment routes their navies expected.