Reports on the 181st leg of the international Ocean Drilling Programme. This leg drilled the ocean floor east of New Zealand to better understand the deep-ocean current system that circulates like a giant conveyor belt through all the world's oceans. The most exciting drill hole was located 450 km north-east of Chatham Islands. It produced a core from a 600-m thick unbroken record of mud and ooze accumulation on the sea-floor extending back 20 million years. (auth/DG)