Crusade (Destroyermen Series #2)

Swept from the World War II Pacific into an alternate world, Lietenant Commander Matthew Patrick Reddy and the crew of the USS Walker have allied with the peaceful Lemurians in their struggle against the warlike, reptilian Grik. But the greatest threat is yet to come. For the massive Japanese battleship that Walker was fleeing back in the Pacific also came through the rift, and it's in the hands of the Grik.