Posted by Tribes on January 27, 2003 at 10:41:47:
Most of the diving here in SoCal is fairly shallow (compared to many of the warm water areas or the east coast). But getting deep here, is real easy to do off our islands, or off some of our deep canyons that come close to shore. Getting deeper on a dive has always been a problem for divers here is SoCal (because we mostly dive shallow). The dangers of deeper diving are potentially far more hazardous then dives conducted in shallower water. For many divers these dangers are not recognized until it was to late. If you look at our local diving accident reports you will see the same mistakes are repeated over and over again.
Tim’s post about “What makes Farnsworth Dangerous” high lights the problems that many divers have got themselves into. Farnsworth has had a long history of diver accident’s. It seems like almost one a year. In the 1980’s 4 divers died on one dive at Farnsworth. There was one last year, and one the year before that and so on. Why are divers dieing? Most SoCal divers today do not have the training, skill, experience, attitude, or the equipment to make deeper dives. Yet they make them anyway. Talking to some of the divers about their deeper diving experiences, I found that most were clueless about the hazards of deeper diving. And most had no idea about deeper diving techniques that could keep them alive.
What is a deep dive?
To me any cold water dive, deeper then 60’ is a deep dive. It has always seemed to me that the ocean is a pretty friendly place down to about 50’ but passed that there are some big changes.
What are the hazards of a deeper dive?
Passed 60’ there is a mark increase in air consumption, you are starting to loose ambient light, you have an increase in Nitrogen intake, you are starting to feel the first affects of Nitrogen Narcosis, deeper diving makes buoyancy control more of a problem, and the depth makes it harder to make an ESA.
All of these factors make deeper diving more of a challenge. Divers need to adapt different techniques to make these type of dives.
What are some of these techniques?
Air Consumption has always been a major problem with deeper diving. You need to manage your gas. One way to do this is by using the rule of third’s. One third for the dive(descent and dive)two third’s to get back to the line. You should always take more gas then you think you will need on a deeper dive(do a sac rate on yourself and see what your air consumption is). You should have a redundant system ( a set of double 80’s with an isolation valve is a good choice, or at lest a larger pony bottle with your single tank). Many divers have been diving single tanks on deeper divers for many years (but a redundant system, will save your butt if something happens, and it will happen, if you do this type diving enough). Use your head. Watch your air consumption and plan your dive around it. Running out air is the most stupid thing a diver can do, and running out of air on a deep dive is fatal.
Decompression Sickness is a real danger on deep dives. It seems that most divers have very little understanding of decompression theory and are dependant on their computers. Blindly trusting your computer without knowledge of decompression theory will get you bent. Divers need to learn about deco theory and use that knowledge.
Nitrogen Narcosis is a problem on all deeper dives and there is not much you can do for, but use a different gas. Narcosis the reason for many the deaths on deeper dives.
It seems that most divers start to feel mild affect of N2 Narcosis from 60 to 100 ft and most divers feel a more pronounced physiological abnormalities form 100 to 130.
To help solve this problem most smarter deeper divers use a gas called Tri-mix. This lets them dive with a clear head.
The use of an up and down line is a must for most deeper dives. The anchor line will help you solve many of the buoyancy issues that come up in a deeper dives. The line assist a diver is there orientation during descent and ascent .
Run a reel or a spool from the anchor line that will get you back to it.
Have a lift bag and know how to use it (you can use your lift bag as an anchor line to come up on if you can’t find the boats anchor line).
Dive as a team not as an individual. Know your buddies strengths and weaknesses.
Know there equipment. Your buddy is an extra air supply, an extra BC, and extra brain.
Training.
To make deeper dives safer, you need more training. You need to take a real deep diving class (not a survey specialty deep diver class put out by PADI, Naui, ssi etc.). You need to find an instructor that has actually made some deeper dives. An OHE class or some of the tech classes will give you the skills to keep you alive on a deeper dive.
Most divers today do not have the skill, experience, attitude, or equipment to make deeper dives. Yet they make them away, and they keep on dieing because of it.
It’s sad to me to keep hearing about new and experience divers dieing on deeper dives. We just don’t seem to learn from the mistakes of the past.
Tribes