<P> In the beginning of World War II the Royal Navy was still the strongest navy in the world, with the largest number of warships built and with naval bases across the globe . Totalling over 15 battleships and battlecruisers, 7 aircraft carriers, 66 cruisers, 164 destroyers and 66 submarines . In the course of the war the United States Navy grew tremendously as the United States was faced with a two - front war on the seas . By the end of World War II the U.S Navy was larger than any other navy in the world . </P> <Table> <Tr> <Th> Country </Th> <Th> Aircraft carriers </Th> <Th> Battleships </Th> <Th> Cruisers </Th> <Th> Destroyers </Th> <Th> Convoy escorts </Th> <Th> Submarines </Th> <Th> Merchant tonnage </Th> </Tr> <Tr> <Td> United States </Td> <Td> 28 (71) </Td> <Td> 23 </Td> <Td> 72 </Td> <Td> 377 </Td> <Td> 420 </Td> <Td> 232 </Td> <Td> 33,993,230 </Td> </Tr> <Tr> <Td> British Empire and Commonwealth </Td> <Td> 19 (46) </Td> <Td> 19 </Td> <Td> 57 </Td> <Td> 335 </Td> <Td> 875 </Td> <Td> 264 </Td> <Td> 21,000,000 (1939) - 22,000,000 </Td> </Tr> <Tr> <Td> Soviet Union </Td> <Td> </Td> <Td> </Td> <Td> 7 </Td> <Td> 59 </Td> <Td> 150 </Td> <Td> 218 </Td> <Td> </Td> </Tr> <Tr> <Td> Japan </Td> <Td> 16 </Td> <Td> 9 </Td> <Td> 51 </Td> <Td> 63 </Td> <Td> 187 </Td> <Td> 167 </Td> <Td> 4,152,361 </Td> </Tr> <Tr> <Td> Germany </Td> <Td> 0 </Td> <Td> </Td> <Td> 12 </Td> <Td> 17 </Td> <Td> 22 </Td> <Td> 1,140 </Td> <Td> </Td> </Tr> <Tr> <Td> Italy </Td> <Td> </Td> <Td> </Td> <Td> 6 </Td> <Td> 6 </Td> <Td> </Td> <Td> 28 </Td> <Td> 1,469,606 </Td> </Tr> <Tr> <Td> Romania </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 18 </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Poland </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 9 </Td> <Td> 11 </Td> <Td> 5 </Td> </Tr> </Table>

Who had the most powerful navy in ww2