:"sea shadow" redirects here. for the 2011 emirati film, see sea shadow (film). {|    |} sea shadow (ix-529) was an experimental stealth ship built by lockheed for the united states navy to determine how a low radar profile might be achieved and to test high stability hull configurations which have been used in oceanographic ships. ==development== sea shadow was built in 1984 to examine the application of stealth technology on naval vessels. she was used in secret until a public debut in 1993. in addition, the ship was designed to test the use of automation to enable the reduction of crew size. the ship was created by the defense advanced research projects agency (darpa), the u.s. navy and lockheed. sea shadow was developed at lockheed's redwood city, california, facility, inside the hughes mining barge (hmb-1), which functioned as a floating drydock during construction and testing. ==history== sea shadow had a swath hull design. below the water were submerged twin hulls, each with a propeller, aft stabilizer, and inboard hydrofoil. the portion of the ship above water was connected to the hulls via the two angled struts. the swath design helped the ship remain stable even in very rough water of up to sea state 6 (wave height of 18&nbsp;feet (5.5&nbsp;m) or "very rough" sea). the shape of the superstructure was sometimes compared to the casemate of the ironclad ram  of the american civil war. sea shadow was built in redwood city, california. the t-agos 19-and-23-class oceanographic ships have inherited the stabilizer and canard method to help perform their stability-sensitive surveillance 
1985_ships Catamarans_of_the_United_States_Navy Experimental_ships_of_the_United_States_Navy High_speed_vessels_of_the_United_States_Navy Lockheed_Corporation Lockheed_Martin Ships_built_in_the_San_Francisco_Bay_Area Small_waterplane_area_twin_hull_vessels Stealth_ships Unclassified_miscellaneous_vessels_of_the_United_States_Navy