High risk, but safe
Scuba diving has an enviable safety record but as with any activity it has a level of inherent risk that cannot be completely avoided - simply reduced.
Everything from equipment manufacturing standards and diver training right through to the way in which dives are constructed and planned (dive profile) is intended to help reduce the risks to the point that diving is generally seen as being a safe sport.
When asked, Dive Bunnies refer to diving as being a high risk activity, that can be extremely safe, provided people approach it properly and are correctly trained.
Essentially, as with many activities, you can make scuba diving as safe, or as dangerous, as you personally choose. What you can’t do is remove all risk.
One such area is the risk of decompression sickness (also referred to as ‘the bends’ or getting ‘bent’).
As recreational sport divers the scuba diving that we do is referred to as no-decompression diving.
This is a complete misnomer that leads some to believe that, provided you stay within the no decompression limits, decompression sickness (DCS) cannot occur, or if it does, it will be the result of patent foramen ovale (PFO).
The reality is that every dive we conduct is a decompression dive.
You will be decompressing during your ascent and the name ‘no decompression diving’ merely refers to the fact that recreational sport divers do not have to conduct staged decompression stops.
So to answer the initial question:
Yes. You can get decompression sickness, even if you dive well within the recreational limits, are properly hydrated and complete your safety stop.
The only way to prevent DCS is not to dive!
No decompression diving
As mentioned above, this is a misnomer. It would be more accurate to describe recreational sport diving as no decompression stop diving.
When we breathe air under pressure we inevitably absorb nitrogen into our body tissues. It is completely unavoidable and our time under the water is restricted by the amount of nitrogen that we absorb.
Air is not the main limiting factor as we could always take more air with us if we wanted to!
When you first learn to dive you will cover what is referred to as your no decompression limits (NDLs). These refer to the maximum time that you can spend at any given depth (or combination of depths) without absorbing too much nitrogen.
When we say too much nitrogen what we mean is that the level of absorbed nitrogen is too high for a diver to proceed directly to the surface. They would need to make a decompression stop (or stops) to manage the rate at which their body releases the absorbed nitrogen.
So no decompression diving is simply a reference term for sport diving that means the diver manages their time at depth to ensure that they can proceed slowly, but directly to the surface.
Remember - a safety stop is not a decompression stop. It is an optional safety ‘buffer’ that is not mandatory and, indeed, should be ignored under certain circumstances (we covered this in our blog Can I ignore my safety stop when diving?.
So I can get Decompression Sickness (DCS) whilst no decompression diving?
Yes - absolutely you can.
And what’s more, you could get DCS despite diving well within the limits and doing everything properly - this is often referred to as an ‘undeserved’ hit - but it is extremely rare.
The numbers vary depending on which research you look at but typically it is thought that for every 10,000 dives, less than 3 incidences of DCS will occur.
Think of it like driving a car. Accidents are actually extremely rare but despite everything you do to avoid an accident (driving sensibly and according to the conditions, keeping you car correctly serviced, not using your mobile phone, etc.) you cannot completely rule one out.
But all divers should be aware of the signs and symptoms of decompression sickness which can appear up to around 12 hours after surfacing, sometimes before a diver surfaces and include:
- Pain in joints, numbness, tingling and/or paralysis
- Fatigue
- Skin itch or a rash
- Shortness of breath
- Difficulty urinating
- Dizziness, confusion, personality changes or bizarre behaviour
- Amnesia
- Tremors
- Staggering
- Coughing up bloody, frothy sputum
- Unconsciousness or collapse
This is part of the reason that having specific dive insurance is so important.
Remember the golden rule: if you have a physical or mental problem after a dive that wasn’t there before, consider DCS as a possible cause.
And remember:
- You can get bent even if your buddy doesn’t
- Your dive computer cannot prevent DCS
- You don’t need to dive deep to have a problem - DCS can occur on shallow dives
- If you suspect a problem - do not try to self treat by getting back in the water
- Oxygen can help but won’t cure - if you feel the need to go on to oxygen after a dive, then you need professional medical help.
What should I do if I suspect I have DCS?
Decompression sickness can be life changing, threatening or even ending.
If you suspect that you or a fellow diver may be suffering from DCS then swift action is necessary. A doctor we know once said, “I’d rather see someone in assessment 10 times than in resuscitation once.” Don’t take any chances.
This Dive Bunnies blog article is not intended to provide any advice or guidance with respect to the treatment of decompression sickness (DCS).
Here, we just want to make sure that recreational sport divers understand that they can suffer from DCS, even if they dive well within the limits and complete their safety stop.
For information regarding the treatment of DCS, Dive Bunnies recommends that scuba divers look to the Divers Alert Network (DAN).
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