Reduced Decompression
There is a worrying trend amongst some divers to reduce the amount of decompression they do to the absolute minimum. Doing the minimum amount of decompression possible is seen as a badge of honour. There are several words which can be used to describe this mindset: crazy, dangerous and irresponsible are just three that spring to mind.This mindset is fuelled by two factors. The first is the ‘macho’ image that some inexperienced tech divers believe is essential in order to appear to be a real technical diver. This, of course, is rubbish.
The most experienced technical divers are the least macho and the most conservative. The second factor is the adherents of particular decompression theories or methods who believe that their theory is so accurate that there is really no need to be more conservative.
Anyone that tells you that they completely understand decompression is either very arrogant or very ignorant. The worlds leading decompression theorists will admit that there are huge areas of decompression that we still don’t fully understand and yet there are divers who will insist that they know exactly what is happening during their decompression.
Most technical divers take the view that if they get to the surface without neurological problems or a pain in the joint then their decompression has been successful. They think that a bit of an itch is just an indicator that they are getting close to their personal limits. However, they may still be storing up long term problems that will not immediately be apparent.
To me there is nothing wrong with taking a conservative approach to decompression and doing a bit more decompression then may be warranted. If, in ten years time, we find the definitive theory of decompression then I would rather find out that I have been doing slightly more decompression than is necessary then to find out that I have been doing too little decompression.
There is very little evidence for the long term effects of Trimix decompression diving. Military and commercial divers have been diving to similar depths using Heliox for many years but there is very little knowledge of the long term impact of Trimix diving. We all know the immediate symptoms of decompression sickness but Hyperbaric Doctors also know that there are long term problems associated with hyperbaric situations. Brain lesions, retinal damage and bone damage are all known symptoms of certain types of pressure exposure.
There are exceptional times when we do want to cut our decompression as short as possible, for example a flooded dry suit in freezing temperatures or container ships bearing down on our position. For all the other times there is no such rush. A few extra minutes of decompression will do no harm.
I am quite happy if I find that I’m the last one back on the boat as I’ve decided to do a few extra minutes of decompression. The other divers may have eaten all the biscuits by the time I get back on board but other than that there is no real disadvantage. On the other hand coming up first may mean that, in years to come, those divers that reduced their decompression to the minimum end up with serious long term health problems.
Mark
For training on how to minimise the risks of technical diving then contact Mark Powell at mark@dive-tech.co.uk or give him a call on 07770 864327
http://www.divingniknaks.com