CHAPTER 1 DOWN IN THE DEEP A team of scientists and explorers is working to map the inside of the Great Blue Hole in Belize The team climbs into a submarine The submarine has a large clear ceiling Water burbles over the machine as it begins its slow dive
At first the water looks bright blue Coral branches out from the rock ledges Sharks and fish swim slowly around When the group reaches 40 feet 12 m they see the first ledge Here the hole becomes a little narrower It starts to get darker They sink deeper and deeper Fewer animals swim around Below 90 feet 27 m the hole gets wider and darker The team uses the submarine's lights to see the surroundings There are caves with stalactites and stalagmites These formations are a sign that the Great Blue Hole used to be a dry cave Eventually the submarine reaches about 300 feet 90 m It looks like there is a cloud in the water A toxic gas spreads out like
Divers can explore the Great Blue Hole's stalactites and stalagmites a blanket It blocks light from the surface Beneath the blank there no oxygen or living things It is completely black
