Peter Snow presents highlights from today's three deep-sea dives around the world. In 2002 BBC organized three concurrent dives , first in Monterey Bay where unmanned submersible is lowered into underwater canyon which is over mile deep. Second dive is in Grand Cayman where submersible Atlantis will explore life at the spectacular Cayman Wall , Kate Humble reports . During the dive, the crew used bait to attract a deep-water giant, the six-gill shark. Third dive takes place in middle of the Atlantic 1200 miles west of Portugal, which is also deepest of the three dives, divers will descent in Russian submersible Mir from research vessel Keldish and the Mir will dive in the bottom of the ocean in 2300 metres .

一架遥控推进器加上两艘载人潜水艇潜入海中的幽冥世界里，他们不但遇上六鳃鲛，还碰到了双髻鲨，甚至还发现一艘沉船，而它的位置深到无法被打捞起来。这一场海底深渊的探险让我们看到一个与众不同、不需要靠阳光生长的自然生态，在海底深处也有高热水柱，其中富含金属与硫化物在深海里漫延开来，一如浓密的黑云；而此地的生物长相怪异，却又丰富多姿，就和科幻小说般的奇幻。