It is not uncommon for divers to get into the water, ready for a dive with the cylinder valve in the completely wrong position. Obviously there are different practices which vary from each agency and experience, however professional divers have also taken notice of some rookie mistakes made by certified divers. The least worrisome scenario is you´d get embarrassed but the most worrisome would be a fatal accident in the water.
Some prevalent reasons for these fatal accidents are as follows:
Not opening the cylinder valve all the way – maybe you got distracted or simply didn´t do a full buddy check, this occurs mostly with people who are inexperienced divers or haven´t dived in a while, but also people who expect the dive centre to ready all their equipment for them. What happens is, in shallow water, there will be enough air supplied, however when you start to descend, ambient pressure starts building and not enough gas will be supplied.
The turn back – One common practice was to open the valve all the way and close it a half or quarter turn, since there was a time when the valve would get stuck open if turned all the way. Today, modern valves have been upgraded so that they don´t stick, so long as every so often the cylinders are serviced.
Cylinder Valve Amnesia – If you aren´t using your equipment for a while, or maybe need to take a boat ride to get to the wreck you are going to dive, it is best to close the valve completely, purge the gas and leave the gauge reading 0 bar\psi. When at said location, suit up and make sure to open the valve fully.
Having a helpful buddy \ dive crew – Although buddies and dive crew are there to help. However, there have been instances where a buddy would close the valve and purge the system, maybe, believing you have forgotten to do so.
Here are some tips and tricks to help you think of checking the valve before entering the water:
1 – Always do a complete equipment assembly, use a checklist if necessary
2 – If you get disrupted during assembling your equipment, start your checklist from the beginning.
3 – In every case, open all cylinders all the way
4 – Always do a thorough buddy check before getting into the water
5 – Always make sure you are close to your diving buddy and make sure you know where your buddy´s alternate air source is and how it functions, incase of emergency.
Having the cylinder valve incorrectly positioned is very much a common error unfortunately. Be sure to check your equipment twice, three times if necessary and a final buddy check never hurt anybody. If you have some time on your hands before your next dive, then have a look at our Equipment Specialist Course, so if you´re a rookie, you will know what to check for on your next trip.