Thursday 30 April 2015

Scuba Divers- 5 ways to improve air consumption

In Scuba Diving, there seems to be just two competitions between divers. These are Depth..."you went to 20 metres? Ha ha! I got 20.1!"

The other is Air Consumption. At the end of the dive, you see divers sneakily checking other diver's gauges to see who came back with the most air because it seems to be readily believed that if you breathe less, you must be a better diver!

Common sense will tell you that this is simply not true and, if you are basing your ability as a diver on the amount of gas you come back with at the end of a dive, you probably want to have a look at yourself and re-assess. Comfort and ability are factors that contribute to breathing rates but, let's face it... if you are a 6 foot lump of muscle you are going to use more air than the 5 foot nothing waif you are buddied with.

However, there are some factors that affect our breathing rates and how fast we burn through a cylinder of air, which we can have some control over and if you want to extend your dive times, here are our 5 tips for doing so.

1. Improve your Fitness

When we do anything that raises our heart rate, we increase our Basal Metabolic Rate (the amount of energy used at complete rest). Whether we are walking, swimming, in the gym or Scuba Diving, more energy is required by our bodies to complete these tasks.

To produce this energy, your body has to metabolise Oxygen, which is harvested in the lungs from every breath we take. So, when we are doing anything physical, we breathe more in order to provide the body with more oxygen to keep up with the demand. 

A person who is unfit may find that the exercise required for Scuba Diving can leave them breathing quite heavily as the body works to pump enough Oxygen-rich blood to the muscles that need it.

Breathing Rate = higher than it needs to be!

A higher level of fitness in a diver, allows the whole process to be more efficient by allowing more Oxygen Rich blood to be pumped with each heartbeat. This efficiency means the diver can achieve the same level of Oxygen reaching the muscles needing it, with a much lower breathing rate.

Improve your general fitness to reduce your breathing rate.

2. Weighting and Trim

Both come under the same heading because, much of the time, one will affect the other.

The biggest cause of high gas consumption we see is Over Weighting. Let's look at how this works...

Consider your local swimming pool. What uses more energy is said pool... swimming through the water or trying to run through the water?

Of course, trying to run through waist deep water will be more energy consuming because you are trying to move a larger surface area against all that resistance in water. This is why we want to be as streamlined as possible when we scuba dive. We are reducing the surface area moving against the water resistance so we are hydro-dynamic.

When we are overweighted, it affects our streamlining in 2 ways. Firstly, it tends to pull down the lower half of our bodies, meaning we are in more of a running position than swimming. This increases resistance and makes it more difficult to move, requiring more energy and heavier breathing.

Secondly, with too much weight, we need to compensate by adding more air to the buoyancy control device. This makes us bigger in the water than we need to be, increasing resistance and requiring more energy and heavier breathing.

See our blog all about Weighting for more information

3. Use the Correct Dive Equipment for the Dive

Prior to going diving, asses the kind of dive you will be making and select the appropriate dive gear for that dive.

For example, if you are diving a wreck known to have strong currents, don't think your pool fins are going to be much use. You want proper open water fins with a good rigid blade that will give you the most efficient fin stroke. More efficiency makes the finning easier and will help to maintain a lower breathing rate.

Another example comes down to temperature. If you get cold easily, there is no point diving in 18 degrees in a 3mm wetsuit. Invest in the exposure suit you need to stay warm underwater. Feeling cold will leave your body trying to generate heat from other sources such as shivering, which requires more energy and will affect your gas consumption.

The final dive kit tip doesn't really affect breathing rate but can alter the amount of gas you use from your cylinder. I am talking about the condition of your diving equipment. Make sure your equipment is in good working order and any leaks have been fixed, o-rings changed and regulators (especially alternates) are not wasting your gas by slowly leaking it out into the water.

4. Improve your Diving Skills

When we first learn to dive, we do tend to use more air and this is because we are busy concentrating on things like our buoyancy and holding a stop or not bouncing along the bottom.

Buoyancy is one of the most important skills you will have as a diver and it is important to make sure it is perfected to the point where you don't have to think about it anymore. You are neutral and in control at all times and you can even multi-task without losing it. 

Once you don't have to spend so much energy concentrating on basics, you will find your breathing rate does decrease.

This leads me on to number 5...

5. Relax and Chill Out

There is nothing more likely to help start your dive the wrong way than stress and anxiety. When we Scuba dive, we need to be relaxed and prepared and this comes from all the previous 4 points but you can start the preparations before you even get in the water.

Get to the Dive Centre early. Make sure you have plenty of time to get all your diving equipment
together so you can make sure everything is there and nothing is forgotten. If anything is broken or not where it should be, you will have time to remedy the fact without stress.

Plan your dive yourself or at least take an active part in it! Knowing what is going to happen on your dives will help you to relax and is a lot less stressful than relying blindly on someone else. It is comforting to know exactly where you are on a dive and thereby, where you are in relation to gas remaining, safety stops etc. Don't be afraid to ask questions about the dive if someone else is guiding. You will get much more out of your dives this way.

On the dive itself, swim slowly and pace yourself so you can conserve energy and breathing gas.

It is what it is!

These are tips to help reduce your breathing rate underwater but, at the end of the day, you breathe
what you breathe and the gas is there to be used. If your guide says s/he needs to turn the dive when someone gets to 100 bar and that someone is you then you must let the guide know. It is much worse to be the one running out of air underwater than to tell the truth and turn the dive. Your guide will appreciate it and so will the other divers in the group.

Never lie about how much air you have left underwater, you are putting both yourself and your buddy at risk. 

Finally, never Skip Breathe. This is one of the worst things you can do for your health and actually makes you breathe more heavily in the long run... at worst you can end up with a Pneumothorax (popped lung) or dead!

So relax, improve your competence and confidence in the water by practicing your dive skills and being correctly weighted with decent, working equipment and try to stay reasonably fit for diving and you will see an improvement. 

Thursday 2 April 2015

Back to Basics- Mask Clearing

Ask a group of divers which is the one skill they could live without and the answer, 9 times out of 10, will be Mask Clearing!

Water around the nose, bubbles up your cheeks and salt getting in your eyes, it is one skill that nobody enjoys.

Although most divers don't even realise it, they probably clear their mask 20 times per dive. Little bits of water creep in when we smile at the fishes or we haven't quite shaved well enough and all in all, there are no problems whatsoever but ask a diver to formally clear a mask and the outcome can be quite different. The thought of completing the skill sends the mind into overdrive and it can take a bit of time to build up the nerve to purposefully let water in.

Mask clearing is however, one of the basic skills to master and the only way to get comfortable with it is to practice, practice, practice! You have to de-sensitise your mind to the water around your nostrils and become confident in the fact that you don't have to breathe it in.

How can I get Confident Clearing the Mask?

I would say the first step to getting used to this feeling can be done while at the surface. While standing in waist deep water, put your regulator in and bend forward, putting your face in the water without the mask on. Take some breaths through your mouth and acclimatise.

Once you are comfortable, you can progress to completing the skill underwater. Start with baby steps, just let a little water in first and clear that by pushing on the top of the frame of your mask while looking up and blowing out through your nose. If you struggle to blow out through your nose with the regulator in, try placing your tongue against the roof of your mouth and then blow.

Move on to full mask floods and Mask removal/ replace when you are happy.

Try opening your eyes and you will find the salt water stings less if you let it wash over the eye rather than fighting to keep the eyes closed. Obviously, if you are wearing lenses, this is a no-no. If you have lenses, keep your eyes shut so you don't dislodge or lose them.

You can start to get comfortable with the skill while kneeling or lying on the bottom but just remember that there are many dive sites around the world where there is no bottom or the bottom is sensitive, such as coral reefs etc. You will not be able to kneel or lie on the bottom to complete the skill at these sites, so you have to make sure you are confident to complete the skill mid-water. Again, the key is practice!

Common Mask Problems causing Leaks

There will always be a little water in the bottom of your mask. This is just the nature of the beast but if you find your mask is leaking excessively, it may be that you are breathing out through your nose rather than your mouth. This breaks the seal and allows water to come into the mask... really irritating.

Another possibility is that you have the mask too tight. The skirt will not sit flat on the face and you get creases and little channels appearing where the skin is squashed together that allow water to get in. Your mask doesn't need to be too tight, the water pressure will hold it in place. Plus a mask that is tightened too much will lead to that lovely red ring all around the face that shows the world where you have been all day.

Sometimes your mask will only leak on holidays or special occasions and you cannot understand why. Think about what you are putting on your face. Have you used sunscreen or moisturiser? Believe it or not, this can affect whether your mask leaks or not!

It is very easy for divers to build up the difficulty of mask clearing in their own heads and a skill that is fundamental to diving suddenly becomes a mountainous task that causes panic and distress. It doesn't have to be that way. Take it slow, make baby steps and become confident and competent in your own ability. Then, there will be nothing to stop you!