A launch system in which an unmanned aerial vehicle is secured to a platform in a watertight tube adapted to be launched from a submerged platform. Once launched, side panels on the tube are jettisoned and a flotation device is deployed to bring the tube to the surface. The flotation device maintains the tube in a vertical position when rising to and at the surface. After surfacing, a top-sealing cap of the tube is opened. A lifting mechanism within the tube raises the vertically oriented platform assembly up within the tube. Guide rails maintain the vertical orientation of the assembly during lifting. At the topmost point of travel, the assembly is raised clear of the tube and is disengaged from the guide rails, allowing the assembly to pivot about its attachment to the lifting mechanism and assume an orientation favorable for launching the UAV.