I'm a big fan of "Alternate History," stories of what might have happened if certain events in the past had never happened or had been resolved in a different manner. I recommend Harry Turtledove and S. M. Stirling if you like to look at alternate realities. One of my newest favorite authors in this genre is Taylor Anderson. His "Destroyermen" series starts of with the last of the Pacific fleets destroyers leaving Manila Bay ahead of the Japanese near the start of World War II. One ship, the Walker, gets driven into a freaky storm which somehow transports them (and others) into an alternate world. In this world, the highest mammalian life form resemble intelligent, vocal, seagoing lemurs; the crew dub them Lemurians. Opposing them are the savage, reptilian Grik, few of whom have any intelligence. The crew decide to throw in with the friendly and endangered Lemurians. Unbeknownest to the destroyermen, the Japanese aircraft carrier pursuing them was also carried throught the storm and have allied themselves with the Grik. And there are other humans in this world, descended from English ships also blown into this world hundreds of years ago. But that's a spoiler from Book two.
Start with INTO THE STORM: DESTROYERMEN, and follow with CRUSADE and then MAELSTROM. If you are a fan of the Navy, WWII, or Sci-fi. give DESTROYERMEN a try.