Real-Life Math -- Solution
In order to determine "total bottom time" add the time required
for the safety stop to the actual bottom time.
Dive 1
For
a dive of 50 meters taking 140 minutes a diver must stop at 10 meters to decompress
for 10 minutes.
140 + 10 = 150 minutes
Dive
2
For a dive of 110 meters taking 30 minutes a diver must stop
at 10 meters for 7 minutes.
30 + 7 = 37 minutes
Dive
3
For a dive of 150 meters with a bottom time of 15 minutes a
diver must stop at 10 meters for 3 minutes.
15 + 3 = 18
minutes
It's important to be careful in determining
your "total bottom time," or you might run out of air.
All divers use
the dive tables to determine how long they need to decompress. Many divers
use "dive computers," which have the dive tables programmed in
them.
Dive tables may vary slightly. For instance, the dive table used
in this exercise specified stops at 10 meters down.
Standard practice,
however, is the following, says dive instructor Mary Brill:
At the
very least, for every dive of 60 feet or more, the diver must stop 15 feet
below the surface for 3 to 5 minutes for decompression.
Brill says
checking dive tables, using gauges and checking computers before the dive
are the best defenses against running out of air or not decompressing long
enough.
Divers should also note that determining the total amount of
air needed isn't as straightforward as it sounds.
"You can have
some amount of air at 60 feet and the same amount at 110 feet and it means
something totally different," she notes. The deeper you dive, the more dense
the air gets and the faster it is consumed.