Malcolm and LB are of course right, but there was a difference between ship and MTB practice. Packard engines were not handed, and the screws (three in most cases, four in Fairmile Ds] all turned the same way. In Vospers the centre engine drove direct, and the two wing engines, set further back in the boat, drove forwards through V-drives, effectively reversing their rotation.
Similarly, aircraft engines were rarely handed. Lancasters, for instance, would probably have been easier to handle with handed engines. The only exception I can think of offhand was the Lockheed Lightning which had handed Allisons.