DARPA is working to develop an ekranoplan called the Liberty Lifter with a payload capacity similar to the C-17 Globemaster. Ekranoplans (or ground-effect vehicles (GEVs)) are among the most interesting vehicles and combine a boat with a seaplane. They have long been seen to have huge potential for military transportation, and while the United States has investigated building ekranoplans, they have never come to fruition.