COUNTRIES from across the Asia-Pacific region are taking part in a search and rescue exercise in Hong Kong aimed at providing the emergency services with essential life-saving training. The United States, Japan, China, and many Southeast Asian countries are all taking part in the annual exercise co-ordinated by the Civil Aviation Department (CAD). The Royal Navy, US Air Force, Navy and Coast Guard are combining with the Japanese Maritime Safety Agency, Hong Kong Marine Police, Civil Aid Services and various government departments in both long and short range operations. The four-day exercise, which began on Tuesday, also includes a symposium, a display of equipment and aircraft and a final debriefing to be held tomorrow. Government Flying Services (GFS) operations officer Pete Goddard said it was a chance for all the relevant rescue services in the Asia-Pacific region, including the Americans who would often assist from their base in Hawaii, to work together. Yesterday saw the simulation of an aircraft ditching into the sea near Sai Kung. GFS S76 helicopters were used to winch ''survivors'' to safety. Land search and rescue techniques are also being conducted with the Civil Aid Service's mountain rescue unit, and today a long range sea exercise takes place with aircraft, helicopters and ships being dispatched to locate targets dropped last night 100 kilometres south of Hong Kong in the South China Sea. All operations are being conducted from a rescue command centre set up at Kai Tak. US C130 Hercules aircraft, a US Navy four-engined P3 plane, and Japanese fixed wing aircraft are taking part. A spokesman for CAD said the exercise would provide training and familiarisation in search and rescue techniques and enhance co-ordination between neighbouring countries.