The Deltic engine at sea and on British railways

What is the best marine engine adapted for locomotive use in Britain?

The Napier Deltic, whose marine-derived engines powered the locomotive class that inherited their name.

The Napier Deltic is the preferred British example of a marine engine adapted for railway use. A pair of Deltic engines powered the locomotive, which inherited the engine's name. Neither contributor can identify another British example, so the claim that it is the only option remains qualified.