STEVE EMBER: Kenny Broad helped organize the Bahamas Blue Hole Expedition. In two thousand nine, a team of scientists spent two months researching blue holes on Bahamian islands including Andros and Abaco. The trip received financial support from the National Geographic Society.
(MUSIC)
BARBARA KLEIN: One reason blue holes have not been fully explored is that they can be extremely dangerous. There are many safety rules that divers must follow to help ensure their survival. First, divers must have training and experience to swim in these caves.
Divers who explore a cave for the first time must establish a thin rope called a guideline. This line helps them to safely enter and exit the cave without getting lost.
Divers must also bring several light sources in case one fails. They also must bring more than one set of breathing equipment in case one device fails. And, they must pay careful attention to their air supply. The rule they follow is to use a third of their air to enter the cave, a third to exit, and a third for emergencies.
STEVE EMBER: There are many difficulties involved in diving in blue holes. In some blue holes divers must quickly swim through a layer of hydrogen sulfide to reach the horizontal caves further down. This gas causes itchy skin, dizziness, and in high enough quantities, death. Or, divers might face extremely strong currents that can suck them into an opening. If they are not careful with their movements they can disrupt an area of a cave, creating explosions of silt which makes it impossible to see clearly. Kenny Broad shows a video of a diver forcing his body through a very narrow rocky opening.
最新
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25