High Quality Content by WIKIPEDIA articles! Sea Fighter (FSF-1) is an experimental littoral combat ship under development (2005-2008) by the United States Navy. Its hull is of a small-waterplane-area twin-hull (SWATH) design, provides exceptional stability, even on rough seas. The ship can operate in both blue and littoral waters. For power, it can use either its dual gas turbine engines for speed or its dual diesel engines for efficient cruising. It can be easily reconfigured through the use of interchangeable mission modules. Helicopters can land and launch on its deck. Smaller water craft can be carried and launched from its stern. The vessel is being developed under the program title Littoral Surface Craft-Experimental (LSC(X)) with a hull type designation Fast Sea Frame. The first vessel has been assigned the hull classification symbol FSF 1 and also has been referred to as the X-Craft. The vessel was designed by British company BMT Nigel Gee Ltd (formerly BMT Nigel Gee and Associates Ltd) who continue with a role in the development of the vessel.