The Ut-1 Ultra Trencher is the biggest sea-sub robot in the world. It weighs about 50 tons and goes as fast as 2 to 3 knots. The purpose of the Ut-1 Ultra Trencher, is to lay down pipes at the bottom of the ocean. Those pipes are used for oil and gas.
Hyperlinks
www.devicepedia.com/ut-1 utlra trencher
www.engadget.com/ultratrencher
www.wikipedia.com/ultratrencher
