Mar 28, 2010 | Freedive Training, Freediving
Free-diving rescue in water.
The vast majority of loss of motor control(LMC) or blackouts happen on the surface though sometimes on rare occasions they can also occur as the diver nears the surface. In the last ten metres the diver should be accompanied by the safety diver who stays within arm’s length.
Underwater approach.
The safety should be alert enough to notice any signs of excessive fatigue or overexertion and provide assistance to the tired diver. If blackout occurs before this can happen the safety should come behind the unconscious diver and reach under their armpit and across their chest with one hand while the other arm supports the head, holding it in such a way that the airway remains closed. This is to avoid entry of water into the lungs. The rescue diver should fin towards the surface in a sideways position to the victim. This allows greater freedom of movement for the rescue divers fins. It’s very important that he tries to come up at the safety buoy as this will help lessen the shock to the victim as he comes around.
Surface rescue.
On the surface the victim should be supported with one hand holding his head well up out of the water in such a way that his airway is fully open. The other hand will very gently slap his face while the rescue diver repeats in a soft voice ‘breath, breath’. The hearing sense is the first to come back after black out and it is very important that the rescue is done in a calm and reassuring manner. The victim may be in a state of disorientation and it is essential that there is nothing done to cause further shock.
Bringing them around gently.
Black out is the last attempt of the body to preserve O2 for the heart and brain as unconsciousness reduces use of O2. Once the body is in a place where respiration is possible i.e. the surface then breathing will resume naturally. We avoid loud noises or abrupt movements because the victim while unconscious is in a vulnerable place and the unconscious mind will react against any situation that seems traumatic by prolonging unconsciousness.
Be tactful.
The affected diver should rest and definitely not dive again that day as there is increased risk of black out after having LMC or blackout. Very often the diver will not be aware of having lost motor control or blacked out. In the water there is no need to make a big deal out of it, wait till you get back on the boat or dry land to discuss the matter. It is important that any lessons that need to be learnt are learnt, but we should avoid a situation where the experience becomes something traumatic. There should be no blame or recrimination. It can happen to anyone.
Mar 27, 2010 | Freedive Training, Freediving
How to be a good buddy.
Discussion of shallow water black out(SWB) in the last post brings us to another important part of elementary free dive training; namely buddy skills.
Proper training.
Obviously for a training partner to be reliable, they should be well trained and experienced. They should be aware of the signs of impending SWB or loss of motor control (LMC) and be well versed in correct rescue procedure. They should also trained in CPR and first aid in the very unlikely event of a serious accident. That said training and experience alone are not enough for a good training relationship.
Trust and communication
Trust and communication are also massively important for a good, safe training relationship between buddies. When you are below you really want to know that your surface support is alert and reliable in case of some unexpected incident. It is very difficult to concentrate on your dive, especially a new personal best, if you feel that the guy on the surface is not paying attention or that he won’t be ready if something goes wrong.
Know thy buddy.
You should know your buddies capabilities and mindset, what they can do and what they feel like doing that particular day. Therefore there must be good communication before, during and after dives. Each diver must know what the other plans on doing at each part of the process. Before the dive, the surface buddy should know the expected depth, duration and form the dive will take. It should be agreed beforehand whether the safety diver will remain on the surface or at what depth he should meet the other on his way up.
Doing safety.
While the diver starts his dive the safety should be in a state of readiness, wearing fins and having completed his breath up. While waiting to descend to meet the diver he should keep a good watch on the time and continue breathing up.
When he meets the ascending diver the safety should be alert and very observant. He should look for signs of fatigue or panic and make his presence known in a non intrusive way.
As they ascend the last ten metres together, the safety should stay close enough to the diver to grab them should it be necessary.
They should reach the surface at the same time at the safety buoy. If the diver forgets the safety should remind the diver to do recovery breaths immediately upon surfacing. The safety should be able to grab both the buoy and the diver should SWB or LMC occur. He should be close enough to the diver to support his head and gently slap his face, while softly urging him to breath.
After the dive there should be some exchange of feedback before they start preparing for the next dive.
Being supportive and non-competitive.
These are only the basic elements of what a good free-dive buddy should do. Apart from this, they should be supportive and understanding. Ideally buddies don’t compete against each other, but encourage the other to do the best they can on that particular day, respecting always the limits as they are on that particular day.
Varying abilities from one day to another.
These variable limits might be personal i.e. physical or psychological or they might be environmental such as currents or visibility. What is important to understand is that what was easy Monday might be difficult on Tuesday and there is no reason to feel disheartened or de-motivated. That’s sometimes that’s just the way it is and no deep analysis is needed. Our physical and mental energy levels fluctuate and we need to accept how we are feeling on a particular day, without ruthlessly pushing ourselves, even if it means that we don’t do a very impressive days diving.
Varying conditions.
Environmental conditions can vary from one day to the next and obviously they can also greatly affect what one feels comfortable doing. Even a mildly stronger current makes a big difference on a deeper dive, possibly changing a dive that is relatively easy without currents to a dive that is potentially unsafe with currents.
Obviously currents can negatively affect our abilities, causing more exertion and use of more O2, but other less obvious environmental variables can also greatly affect our capabilities, such as visibility or changes in temperature. Diving to fifty metres in crystal clear waters is a very different thing to diving through fifty metres of near darkness. It can also be very discouraging to dive into a cold water thermo-cline, while trying for a new personal best, especially if there is an accompanying drop in visibility. Another cause of stress can be choppy surface conditions, making it hard to relax and focus before a dive.
Acceptance of what is.
Clearly there are quite a few variable factors that can affect our performance and sometimes it’s not necessary to know exactly why you’re not at the top of your game, sometimes quite simply we have ‘off’ days. The important thing is to accept the limits as they stand in that particular moment and a good buddy should always help you with that, while still encouraging you to do the best that you’re comfortable with.
Nov 10, 2009 | Freediving, Physiology of free-diving
The mammalian dive reflex (MDR) is part of our evolutionary heritage that all humans possess to some extent. In extreme situations such as near drowning it helps by increasing our survival time, but normally in most people it is a reflex that lies dormant. Though dormant it, like most reflexes, can be honed and developed. (more…)
