From Popular Science :
Lockheed Martin’s Skunk Works, famed for the U-2 and Blackbird spy planes that flew higher than anything else in the world in their day, is trying for a different altitude record: an airplane that starts and ends its mission 150 feet underwater. The Cormorant, a stealthy, jet-powered, autonomous aircraft that could be outfitted with either short-range weapons or surveillance equipment, is designed to launch out of the Trident missile tubes in some of the U.S. Navy’s gigantic Cold War–era Ohio-class submarines.
The Cormorant does not shoot out of its tube like a missile. Instead an arm-like docking “saddle” guides the craft out, sending it floating to the surface while the sub slips away. As the drone pops out of the water, the rocket boosters fire and the Cormorant takes off. After completing its mission, the plane flies to the rendezvous coordinates it receives from the sub and lands in the sea. The sub then launches a robotic underwater vehicle to fetch the floating drone.
The Defense Advanced Research Projects Agency (Darpa) is funding tests of some of the Cormorant’s unique systems, including a splashdown model and an underwater-recovery vehicle. The tests should be completed by September, after which Darpa will decide whether it will fund a flying prototype.
Um. My initial reaction is that this is such an egregious violation of the KISS principle I have strong doubts it will ever be practical. But it would be soooo COOL!