THE Sunday Money report (April 18) on the development of Yantai, ''close to Hongkong's northeast border'' showed a touch of understatement. According to most of the recent GIS maps, the border follows the coastline all the way around Mirs Bay. Does this mean that any piers or landfills at Yantai that project beyond the high water mark actually belong to Hongkong? In this sense Yantai is already an ''extension of port facilities in Hongkong''. Opening the port to international shipping is a good idea but it seems that the ''regular shipping routes'' from Hongkong so far comprise mainly vessels heading for Vietnam, which is in the opposite direction. JOHN BOWDEN Hongkong