Contact:  Jeanne Kouhestani            FOR IMMEDIATE RELEASE
                                       5/14/98

The NOAA ship RUDE that was instrumental in locating the wreckage of TWA Flight 800 on the bottom of the Atlantic Ocean in 1996 is back in the New York area, conducting hydrographic surveys between Montauk, N.Y., and Block Island, R.I. The surveys will be used to update nautical charts, including some areas that haven't been surveyed since 1933, the National Oceanic and Atmospheric Administration said today.

"RUDE is using state-of-the-art multibeam technology and side-scan sonar to provide full bottom coverage maps of the area," said Commanding Officer Lt. Cmdr. David Cole, NOAA Corps. "These maps will provide accurate depths and positions of dangers to navigation, and will update areas that haven't been surveyed since 1933. We're doing this project in response to requests from the Northeast Pilots Association for updated nautical charts in the southern New England area, which is traversed by petroleum tankers, freighters, barges, cruise line vessels, U.S. Navy vessels, and fishing boats."

RUDE conducts hydrographic survey operations off the U.S. Atlantic and Gulf coasts. The ship specializes in multibeam sonar, sidescan sonar, and diver investigation of submerged wrecks and obstructions to navigation for the update of nautical charts. RUDE, in fact, using its hydrographic survey capabilities, located the major debris fields from the wreckage of TWA Flight 800 within 48 hours of the crash off Long Island. The ship was working near Pt. Judith, R.I., at the time, and was one of the first federal ships to arrive on scene.

RUDE carries some of the most technically advanced hydrographic and navigation equipment available, including Differential Global Positioning Systems, a Multibeam Bathymetric Sonar System, and Side Scan Sonar (SSS). The ship is equipped with several hydrographic data acquisition and data processing systems. The ship is also fully equipped for diving operations to allow determination of the precise nature of submerged obstructions.

When conducting a search for an underwater obstruction, RUDE deploys a side-scan sonar and multibeam bathymetric sonar system. Housed in a small torpedo-shaped shell called a "fish," the SSS provides an accurate acoustical image (sonogram) of the bottom extending up to 100 meters on each side of the ship. The actual amount of bottom coverage attained is dependent upon the depth of water, the towfish height and specific water characteristics. During typical survey operations in depths between 10 and 60 meters, a 200- meter-wide bottom swath can be examined as the fish is towed slowly astern. All potential hazards to navigation identified using SSS are further investigated using the multibeam bathymetric sonar system and ship's divers to determine the precise extent of the hazard and the minimum depth of clearance. In addition, an accurate position and description of the hazard is obtained for charting purposes. Typically, 100 percent multibeam coverage is obtained concurrently over the entire survey area. Minimum depths critical to navigation are then generated from a survey file, which may exceed 60 million depth soundings.

RUDE is one of only three hydrographic survey vessels remaining in the NOAA fleet tasked with updating the nation's charts. NOAA ships are operated and managed by officers and civilians of the Office of NOAA Corps Operations. The NOAA Corps is a uniformed service of the United States, composed of officers all scientists or engineers who provide NOAA with a useful blend of operational, management, and technical skills that support the agency's programs at sea, in the air, and ashore.