C. Alexander London - Blood In The Water [Kindle azw3]

Based on a real military program! The US Navy's new breed of soldier is ready to make a big splash. From the author of Dog Tags! Navy SEALs are some of the most elite warriors in the world. Trained to operate in sea, land, and air, they work under cover of night to carry out the US military's most sensitive and difficult missions. Cory McNab wanted to be a Navy SEAL, but he washed out of the program. Now he is a member of the Navy's Marine Mammals Program, where he is partnered with a search-and-recovery dolphin named Kaj. Together, Cory and Kaj are the Navy's best hope when a US spy submarine is lost in enemy waters. With the help of Kaj's bio-sonar, they should be able to locate the submarine before its secrets fall into the wrong hands. But the mission gets complicated when a team of Navy SEALs runs into trouble. Can Cory succeed where his heroes have failed . . . or is he in too deep?