Page 338 - Hawaii: Diving, Surfing, Pearl Harbor, Volcanoes and More

eorge Benjamin, a professional pho- nitrogen narcosis and an increased risk of depths as they explore the wall. Those div-
G tographer and the first blue hole ex- decompression sickness, associated with ing from an anchored boat often dive at
plorer, did hundreds of wall dives from the deeper diving. one depth during the against-the-current
Berry Islands to the southern tip of Andros leg and ascend to a shallower depth for the
in the 1950s and ‘60s. He is quoted in Rob ince the majority of walls are effec- return leg. Having something to explore at
Palmer’s book, Deep into Blue Holes: “Going S tively bottomless and the water often any depth is one of the attractions of wall
over the edge of the wall is like flying a gin-clear, it is easy for a diver to descend diving — you can begin ascending from
small plane into the Grand Canyon - and the beyond the planned maximum depth, even your maximum depth and still have plenty
descent is like slowly falling down a huge beyond the sport-diving limit: 130 feet or of diving left before reaching the top of the
mountain face? I feel an absolute, timeless 40 m. That is one obvious reason why buoy- wall.
silence, which I cannot easily describe and ancy control is a critical skill for wall divers.
which is, for me, unique. I fully understand Because a diver becomes more negatively ince wall diving often involves diving
Cousteau’s choice of title for The Silent buoyant as he descends, it is important that S deep, wall divers should watch for the
World.” he add air to his buoyancy compensator onset of nitrogen narcosis, a physiological
as he goes deeper on the wall. This slows condition that occurs when the nervous
all Diving is not for the poorly the rate of descent and makes it easier to system is exposed to increased nitrogen
W trained or rusty diver. It does not establish neutral buoyancy upon reaching pressure. Nitrogen narcosis usually oc-
require unusual physical conditioning or the desired diving depth. curs at depths of 100 feet (30 m) but some
special skill development, but good diving divers may begin to feel its effects at shal-
fitness and mastery of basic scuba skills are egardless of the environment you dive, lower depth
a must. Excellent buoyancy control, astute R the deepest part of your dive profile
depth, air supply and bottom time moni- should be done first. Wall divers generally
toring are important. Divers must under- descend to their maximum planned depth,
stand the physiological challenges, namely and then ascend to progressively shallower