What happens if the Napoleonic navies receive World War II equivalents for every ship they possess?
Short answerThe Royal Navy's existing numerical advantage becomes overwhelming, as long as the scenario also supplies the fuel, ammunition, crews, and maintenance its modern fleet requires.
NotesThe counterfactual gives every navy from 1803 to 1815 a broadly equivalent World War II vessel for each sailing warship it historically possessed. The mapping treats frigates as destroyers, razees as heavy cruisers, and major ships of the line as battleships or aircraft carriers. Because the Royal Navy operated such a large worldwide fleet, a ship-for-ship conversion would produce an enormous modern force compared with its opponents. That advantage only works if Britain also receives the fuel, ammunition, trained personnel, repair infrastructure, and other logistics needed to operate twentieth-century ships. With that assumption satisfied, the numerical imbalance would make the Napoleonic naval war overwhelmingly one-sided.