April 19, 2012: The U.S. Navy has announced that is has selected a UUV (Unmanned Underwater Vehicle) to be used by LCS (3,000 ton Littoral Combat Ships) for mine sweeping. The new Knifefish UUV will be the size of a torpedo and won't be ready for service until 2017 unless, of course, there are development problems. There has long been uncertainty over which UUV the LCS would use because there are some in use for mine hunting already.

For example, there are several versions of the commercial Remus 600 UUVs being used for underwater reconnaissance (including searching for mines). The U.S. Navy has also used the similar, but smaller (26.4 kg/80 pound), Remus 100s for this in Iraq and the Remus design is highly regarded.

Remus 600 is a 240 kg (528 pound) pound vehicle that looks like a small torpedo. It is 3.25 meters (10 feet) long and 320mm in diameter. Carrying a side scanning sonar, and other sensors, a Remus 600 can stay under water for more than 24 hours, traveling at a cruising speed of 5.4 kilometers an hour (top speed is nearly twice that). The UUV can operate up to 100 kilometers from its operator and dive to 600 meters (1900 feet). The UUV keeps costs down by using GPS, in addition to inertial guidance. The UUV surfaces every hour or two to get a GPS fix and then goes back to doing what it was programmed to do.

Remus 100 was designed mainly for civilian applications (inspecting underwater facilities, pollution monitoring, and underwater survey or search). But there were similar military and police applications, like searching for mines or other terrorist activities. Belgium, Australia, and New Zealand also used Remus 100, and over a hundred are in use. This success led to the development of the larger Remus 600, which is used by Britain and the U.S. Depending on sensors carried, each Remus 600 costs $500,000-1,000,000. The Knifefish will probably be a lot more expensive, larger, and have more capabilities.