The U.S Navy wants you to solve this puzzle

Hey all you code-breaking, cryptology-loving millennials out there –- you know who you are -– the U.S. Navy has top-secret puzzle for you to solve. You’ll have 18 days to figure it out from serial clues served up via social media and, if you’re a true super sleuth, you’ll save the world.
Well, not exactly because the digital game is fiction, as is the backstory of a Dr. Evil-style villain who has stolen the plans for a high-grade Navy weapons project. A Navy cryptologist has stowed away on the getaway submarine, headed to “a secret island lair,” and will post encrypted messages each day. Players will have to decipher her increasingly obscure clues, figuring out the location and destination of the sub and ultimately catching the shadowy bad guy