How the Royal Navy could use the French fleet in 1940

French cruisers, destroyers, carriers, and fast capital ships would relieve British shortages, but their missions would depend on speed, maintenance, ammunition, and existing support.

Question

Which French ships would the Royal Navy have wanted if the Marine Nationale joined it in 1940?

Short answer

Most were useful, especially modern cruisers, destroyers, Dunkerque, Strasbourg, Richelieu, Jean Bart, and even Béarn in a support role.

Notes

Most Marine Nationale cruisers, destroyers, and capital ships would be useful additions to an overstretched Royal Navy. Dunkerque and Strasbourg could reinforce Force H, while Richelieu and Jean Bart would be valuable fast counters to German capital ships and Béarn could serve as an aircraft ferry or escort asset. French light forces would strengthen the Mediterranean Fleet and free British destroyers and battlecruisers for other work. Their deployment would still follow the support network: specialized ammunition, engineers, and spare parts make home waters and the Mediterranean easier than a distant Far East station.