Oceanographic and hydrographic survey ships are used to study the world's oceans. The collected data helps to improve technology in undersea warfare and enemy ship detection. The oceanographic and hydrographic survey ships' multibeam, wide-angle precision sonar systems make it possible to continuously chart a broad strip of ocean floor. Two oceanographic ships survey the sea bottom and collect hydrographic data, charting three-fourths of the world's coastlines. USNS John McDonnell (TAGS 51) and USNS Littlehales (TAGS 52) make it easier for navigators to find their way along well-traveled and not-so-familiar shipping routes.

Features: The Silas Bent class of surveying ships were designed specifically for surveying operations. They have a bow propulsion unit for precise maneuverability and station keeping.

The John McDonnell class of survey ships carries 34-foot survey launches for data collection in coastal regions with depths between 10 and 600 m and in deep water to 4,000 m. A small diesel is used for propulsion at towing speeds of up to 6 knots. SIMRAD high-frequency active hull-mounted and side scan sonars are carried.