This was the US Navy's cutting-edge stealth ship

In the early 1980s, Cold War tensions were at their post-Cuban Missile Crisis height, and the US was looking for any strategic advantage it could get against its Soviet adversary.

Although submarine-based missiles were a well-established leg of the nuclear "triad" (along with ballistic missiles and strategic bomber aircraft) the US realized the strategic applicability of stealth for vessels at sea. Specifically, US military researchers wanted to test the viability of making nuclear-armed submarines invisible to sonar.

This effort resulted in Lockheed Martin's experimental stealth ship, a razor-like surface vessel called the Sea Shadow.

First acquired by the US Navy in 1985, the Sea Shadow remained secret until it was unveiled to the public in 1993. The ship continued to be used for testing purposes until 2006, when it was removed from service.

Built with help from DARPA and funding from the US government, Sea Shadow was designed to test if it was possible to construct ships that could be invisible to Soviet satellite detection systems and X-band radar.

Additionally, the ship was more highly automated than previous vessels, and the Sea Shadow was partly aimed at testing how well surface ships could perform under the command of a very small crew.

First acquired in 1985, the Sea Shadow was never intended to be mission capable.

Instead, the ship was built to test stealth and automation technology. The sharp angles on the ship reflect designs that had previously proven successful for Lockheed's stealth Nighthawk attack aircraft.

The Sea Shadow's raised hull builds upon older technology that is widely used in ferry design for enhancing stability. The Sea Shadow was designed to be able to withstand 18-foot high waves.

The Sea Shadow was small and cramped. It was only 160 feet long, could only fit 12 bunks, and only had a small microwave, refrigerator, and table for the crew.

Although the Sea Shadow was taken out of service in 2006, it still influenced later classes of ships. Its low radar cross section, for instance, informed the design of subsequent US Navy destroyers.