The US elite force Navy Seals has shown considerable interest in the Norwegian high speed patrol boats of the "Skjold" class, built with stealth technology. This makes the vessels difficult to detect by radar.
The US Navy had one patrol boat on loan for a year for test purposes, and the Norwegian Umoe Mandal Yard has now entered into a contract with the Navy Seals for a further study and evaluation of the suitability of the new patrol boats for US purposes.
The Swedes also have a stealth ship, but the Norwegian ship is apparently superior to both the Swedish and American stealth projects currently underway. These craft will become increasingly important with looming (and in some cases current and covert) littoral warfare and anti-piracy efforts, Not to mention penetrating the coast lines of potential adversaries.