The U.S. Navy has sent the Norfolk based salvage rescue ship USS Grapple (ARS 53), shown in this file photo, to assist in the underwater search phase of the Swissair Flight 111 crash near Halifax, Nova Scotia. On board the Grapple will be a newly-developed Synthetic Aperture Sonar and a Laser Electro-Optics Identification System, both of which will provide detailed images of the ocean floor. The synthetic aperture sonar was developed to identify underwater mines as part of the Navy's countermines mission, but other applications such as salvage and recovery operations and environmental cleanup are also uses for this advanced imaging technology. The laser electro-optics identification system uses dual frequencies to detect and classify objects suspended in the water column as well as those that may be buried or partially buried in the ocean floor. The Grapple has 20 assigned divers and is assigned an additional 12 divers from the Mobile Diving and Salvage Unit, Norfolk, Va. The Grapple was used two years ago in the recovery efforts of TWA Flight 800 from the waters of Long Island Sound.