The United States converted two large Great Lakes paddle steamers into USS Wolverine and USS Sable for carrier qualification. Existing wide hulls could accept useful flight decks without building new propeller-driven training ships or diverting combat carriers. The lakes provided an extensive sheltered operating area that other countries would have treated as a small sea. By contrast, the Royal Navy used whichever escort carrier could be spared in the Irish Sea. Geography and available hulls shaped different solutions to the same training requirement.
Chapter · 35:18-37:30
Why Great Lakes paddle steamers became training carriers
USS Wolverine and USS Sable turned wide, available freshwater paddle vessels into carrier-training decks without diverting ocean-going combat hulls.