WASHINGTON, Aug. 13 (Xinhua) -- The newly-developed underwater robot Sentry has successfully completed its first scientific mission, the U.S. National Science Foundation reported on Wednesday.

　　Capable of diving as deep as 5,000 meters into the ocean, Sentry has surveyed the seafloor of the northwest Pacific during the July 22 to Aug. 5 expedition.

　　Scientists from the Woods Hole Oceanographic Institution and the University of Washington are in charge of the mission.

　　Sentry surveyed 212 linear kilometers of seafloor, or about 53 square kilometers, as it traced parallel lines like a lawn-mower making a pattern across a yard.

　　It gathered the most precise maps to date of seafloor features known as Hydrate Ridge and Axial Volcano off the coast of Oregon and Washington. It helped pinpoint several proposed deep-water sites for seafloor instruments that will be deployed in NSF's planned Ocean Observatories Initiative.

　　Sentry is a free-swimming underwater robot that can operate independently, without tethers or other connections to a research ship.

　　The autonomous underwater vehicle, or AUV, is pre-programmed with guidance for deep-water surveying, but it can also make its own decisions about navigation on the terrain of the seafloor.

　　"This investment into emerging technologies is paying off in delivering state-of-the-art science support," said Julie Morris, director of NSF's Division of Ocean Sciences. "In the near future, Sentry will conduct high-resolution oceanographic surveys that would be otherwise impossible.