Avoid them, it's better for you.
Dear readers,
Happy Monday, and I wish you a good start of the week.
So what should we review today? Well, as always, there are plenty of topics to review. Now considering that some of you will get back in the water after an more or less extensive time away from diving, I thought of bringing you a mini-series about the most common mistakes divers do and how to avoid them. Nothing too technical, basics plus common sense!
Mistake of the day: Poor Buoyancy
You buoyancy isn't perfect? It happens to the best of us. Nothing to be shy about working your buoyancy continuously. Even the very experienced divers keep trying to improve their buoyancy. It is a never ending task. Nevertheless, you should (or I should say must) have a reasonably good control, be it only for you safety.
Many injuries are directly related to a poor buoyancy control. Let's have a look.
Marine life (you touch something you shouldn't have because you don't control your move). You don't want to hit a rock or touch a scorpion fish do you? In other words, protect yourself from the environment.
"Think twice before you touch me"
Uncontrolled ascent (you shoot to the surface although it was not your intention) which can translate into decompression issue, lung overexpansion and pulmonary problems, risk of arterial gas embolism. Ok don't want to scare you, these are extreme scenarios but it doesn't mean the risk doesn't exist. We are willing to take the risks, but in a controlled manner, as much as possible.
Best Practice: buddy signals ok during a controlled ascent.
Uncontrolled descent (you sink, somehow) and go beyond your dive plan. Sounds ok right? Wrong. It is less risky than an uncontrolled ascent from a physiology angle yet it can be problematic. Going deeper than the plan can increase your air consumption (both the one you breath and the one you may burn playing with your BCD to adjust buoyancy). As a result, you may be low on air much faster than expected and, for those less experienced, impact your air reserve to ascent safely. Also, you may be suject to narcosis going deeper, which in turn may add extra risk to your dive.
Equalization, I am referring here to your hears. Some are sensitive, some don't. No right or wrong, just descent are your pace. Now an uncontrolled descent can turn very uncomfortable if not painful for your ears. If you are not capable to control your pace, you will not be able to equalize on time for the pressure. On the other way round, during the ascent, you could face a reverse block and the only way to compensate is to descend a little bit. Without buoyancy control, you may find it difficult to adjust to the pressure.
To add (I promise it will be my last scary point), these threats, perceived or real, could potentially generate stress. Too much stress could lead some divers to have a tunnel view (focus on one task, losing the big picture) or, in the worst case, to panic. We don't want that.
If it happens, remember: STOP, BREATH, THINK and ACT.
What to work and what to consider?
Practice and a bit of technique. Your buoyancy is based on different factors.
Your type of exposure, e.g. thickness.
Equipment, e.g. tank size and composition (steel or aluminium).
The environment, e.g. fresh waters vs salted waters, the current to some extend.
Your capability to naturally control your buyancy, e.g. via controlling your breath.
The usual suspect to monitor? Weighting.
You probably know how much weight you need. Usually, you set it once and you are good. Well, unless you put on weight (or the opposite, but it rarely the case let's be honest, or maybe it's just a Bears' problem). That said, there is nothing wrong testing a different weighting from time to time, I like to to that. Add or remove one kilo just to see how it goes. It also depends how much material I take with me. For a beach dive I am usually light. For a night dive I may be heavier (two torches, a rescue signal, maybe a hook for the current). So fine-tune the weight based on the dive profile too. In any case, your weights are here to allow you to descent, not to sink.
Still not too sure? Do a predive buoyancy test. Its quick an easy, three steps.
1. Enter the water (fully geared up) with your BCD fully inflated.
2. Breathe in and hold a normal breath.
3. Hold your breath, slowly let all of the air out of your BCD.
You should float at eye level with the water. If not, you are not properly weighted.
Closing remarks
Your BCD isn't meant to go up or down. You can use it a bit at the beginning of a dive to marginally adjust your buoyancy but don't dont that all the way. It would also consume your air very quickly.
Throughout the dive, your buoyancy will evolve. As your consume air, your tank gets lighter and more buoyant (which will pull you up).
When you ascent, the air stuck in your suit (I assume a wetsuit here) and in your BCD will expand, which will increase your buoyancy (and pull you up).
Conclusion?
Spend time working your buoyancy. Your dive will be more fun and safer.
Happy diving!
Sincerely yours.
The Diving Bear
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