APRIL 1997: Standing at the edge of North Sulawesi's Tangkoko Reserve, the view of the marine park below him promised to provide some spectacular diving. So it came as a shock during his first snorkeling outing to find that the waters were spookily empty. The reason for that, as Robin was soon to discover, was a "Wall of Death" surface-to-floor trap net that extended from the shoreline of the national park to the deep sea drop-off. A Taiwanese f