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 ..