The basic issue of diving is the pressure of the surrounding water in which we are diving. Dive down to just 10 metres and the ambient pressure is double what it is on the surface. Go down to the 30 metres recommended to Advanced Open Water divers and you are experiencing 4 times atmospheric pressure.

This is a huge variation in air pressure and with just a slight change of air pressure we would be unable to expand our lungs and suck in air. Therefore, the regulator needs to provide air at around the pressure of the water around us.

But on the other hand, at the surface when you test your air supply you could be sucking in air from a tank which is at a pressure of 200 bar – that’s 200 times atmospheric pressure. If you were to breathe air at this pressure your lungs would explode.

So the job of a diving regulator is to provide the diver with air at the same pressure as the water around the diver, for comfort and safety.

And this takes place in two stages and the names are the big clues to how this work – with a first stage and a second stage regulator.

The first stage regulator attaches to your tank and reduces the air pressure to a pressure that is higher than you are likely to need, whilst low enough to be safe within the high pressure tubing that goes between the stages.

The second stage regulator takes in the lower (but still too high) pressure air and reduces it to the the same pressure as the water around you. This means that it is perfectly easy to breath in and very comfortable.

But, how does it do this?

Well in each stage there will be a piston or a diaphragm. Whichever is used is probably not really of interest to the diver, but basically the high pressure air on one side pushes it open, whilst it is assisted on the other side to close it when the pressure is sufficient. Therefore, the valve opens slightly to allow some air in, which raises the pressure (or example in the tubing) and once that hits the desired pressure it is assisted to close the valve, until the pressure is reduced (by the diver breathing in), which starts the process moving again.

Both stages use the same basic techniques, with the second stage being opened by the pressure of water pressure, which is what converts the air to a breathable pressure.

                          

For most people, becoming a certified diver is about taking the PADI Open Water Course. It is not the most basic course that they offer, but it is the most basic that offers the freedom and flexibility to dive with an organised group. So, what is involved?

1) A swimming test
2) Some simple studying
3) Confined water training
4) Open water training
5) An exam!

The swimming test
Don’t worry, this is not as fearsome as it sounds and is just a check that you can handle yourself in the water and won’t panic and drown on your first outing. You just need to show to your instructor that you can manage a 200 metre swim and then tread water for 10 minutes. It doesn’t matter what stroke you use or even if it is a recognisable stroke. Just do the lengths and stay afloat.

Simple study
There are a variety of modules to study from how to kit up, pre dive safety checks, what to do in an emergency and simple tasks such as removing and replacing your mask. Your instructor will make various tools available to you in order to ensure that your training is interesting and the lessons are learned, such as DVDs and written manuals. And each is followed by a quick review test!

Confined water training
Jump into a swimming pool and start practising those skills you have been watching. From simple tasks such as clearing water from your mask to slightly more complicated navigation exercises and buddy breathing. None of it is too complicated and your instructor is there to help you through every step of the process.

Open water training
This is where the fun begins with 4 shallow dives. On the first you will repeat the exercises you have gone over in the pool, such as mask clearing, before actually heading underwater for a shallow dive. Each of the 4 dives is mainly for enjoyment and experience, but there will be occasional tasks and each one will be a little deeper than the one before until you should reach about 18 metres (your maximum qualified depth) on the 4th dive.

The final exam
Every PADI course seems to involve an exam and here is this courses! A set of relatively easy multi choice questions. If you have done the lessons, the confined water and an open water dive or two then there should be no problem scoring highly on this course. And as I got 100% then it can’t be too difficult!

So, if you are up for an adventure, whether it is when you are on holiday somewhere exotic or even more frequently whilst you are at home, the Open Water certification opens up a whole new underwater world to you and you will enjoy it and get a lot out of the course.

                          

Hand signals
For a start, hand signals play a big part in underwater communication. There are a whole array of standard signals, including “are you cold”, “OK”, “short on air”, “ascend” and many more. You will be taught these when you learn to dive.

Also, depending on how and where you are diving there may be a few extras that your group might agree upon before you dive and your dive master will almost certainly go through a few simple signals before the dive starts that will be used – mainly asking how much air you have left and the replies to use. These will include a signal for 50 bar (or whatever point you will begin your ascent by) and every 10 bar of air above that.

Attracting attention
Of course, none of this is any good unless the divers are looking at each other, so we have a few ways of attracting the attention of other divers as and when needed.

The simplest is a rattle type of stick. By tilting it there is a rattling noise and this alerts everyone to the fact that the holder wants to communicate. More obvious is some sort of tank banger. This can either be an elasticated device fitted to the air tank before the dive, or if you are carrying a knife then that usually has a metal and to the handle, with which you can bang your own air tank. Hit hard, it creates a lot of noise and everyone knows someone wants attention.

More general communication
Once you have someone’s attention then a few hand signals might not be enough, especially on a dive in which you are undertaking some form of task. So, there are more ways to communicate.

And for this you can carry with you a basic underwater slate and a marker pen. You then just write your message on the slate, hold it up and your buddy and other divers can then pass back hand signals, or repeat the written messages.

Of course, the prepared diver does also on occasion take down with them these slates with messages pre written on them. Just hold up the relevant message and the job is done.

High tech communication
If you have watched a TV program in which the presenter is diving you will have seen the latest idea, which is a full face mask, which includes microphones and speakers to aid communication. However, not only is this gear expensive, but if the regulator malfunctions then you are without a mask, so specialist training is needed here.

                          

It’s the highest PADI course to take for an amateur and with 5 speciality courses added to it, you can apply for the Master Diver rating – the highest non-professional award you can take with PADI. But best of all, the course teaches you a lot of useful skills. What is involved?

1) A first aid course
2) Learn some theory
3) Practice it in the water
4) Take a final exam

First Aid course
Depending on where you are taking your Rescue Diver course, if you have not already got a current First Aid course then they might be able to offer you a combination of the Rescue Diver course along with the First Aid course. It is a requirement of qualifying that you have a current First Aid certification, so that you have an understanding of what to do with a patient once extracted from the water. Some training centres might also add in the Oxygen Administration course (which I did), which teaches you the benefits of and how to use Oxygen. Very useful, given that most diving accidents result in giving Oxygen!

Learn the theory
How do you approach the victim? What should you be looking for prior to a dive? How do you search for a missing diver and bring them to the surface. There is a lot to learn, but it is an interesting subject to study and this is where you learn a lot that will help to keep you safe in the water.

After this you head to the water and practise the lessons so that you become familiar with what is involved and really learn everything that is needed.

Practice in the water
Now your group will spend about a day simulating accidents and diving problems, with each member of the course taking it in turns to lead the rescue whilst the other members are the rescuers. And this is where the course can become fun and you learn a lot as it becomes realistic with lots of instructors and volunteers involved. You probably won’t know what’s coming up next, but it is an excellent day!

The final exam
Where would a PADI course be without the final multiple choice assessment?

So, if you want to learn more about not just rescuing other people but also about getting yourself out of problems and want to take your diver education further then I can wholly recommend that you book yourself onto a Rescue Diver Course and give it a go. It can be excellent fun!

                          

It might not come as much of a surprise to you, but the actual answer to the question of “How Much Pressure Can Your Eardrum Take?” is “Very little.”

What pressures are involved?
The basic equation is that for every 10 metres you dive down under water, the pressure on every part of your body increases by 1 atmosphere. So at 10 metres down you are experiencing 2 atmospheres, at 20 metres 3 atmospheres and so on.

Follow this carefully and you notice that in that first metre of diving the pressure goes from 1.0 atmospheres to 1.1 atmospheres – an increase of 10%. Deeper down, say around 20 metres, the problem is a lot less. from 20 (3.0 atmospheres) to 21 metres (3.1 metres) is “only” an increase of 3.3%.

Those first metres
It’s that first metre or two where the highest proportional increase hits the diver, but every metre deeper adds on 0.1 atmospheres. You only need to dive to the deep end of a good sizes swimming pool, where you can maybe hit that 2 metres deep mark, and you will experience the start of the pain in your ear drums showing you that the pressure is too much.

What causes the problem?
The problem isn’t the pressure around you, it is the imbalance of pressure. If the water pressure around you is at 3.0 atmospheres and the air in your inner ear at 1.0 atmosphere (surface pressure) then there is an extreme force on one side of your ear drum and not the other. This will cause it to bend inwards, cause you pain and rupture. This must be avoided!

The fix
The solution to this is simple. The pressure can be equalised on either side of the eardrum, so that (for example) at 20 metres the pressure on both sides is 3.0 atmospheres. With it being equal, there is no pressure difference and no pain.

But to equalise (which is how you release the pain in a flight) you need to allow air through the eustachian tube, which runs from your nose to the middle ear, behind the ear drum. But to be able to do this you need to be able to breath fully through your nose, else this tube can be blocked. That’s why divers cannot dive with a cold!

So, how much pressure can your eardrum take?
The answer is as I have already said not much, but that is not much difference between both sides of the ear drum. A difference of 0.2 atmospheres is more than enough to cause discomfort. But by equalising every metre as you ascend and descend that difference can be kept in the safe region and other problems are an issue, not your ear drums.

                          

Sorry, here we are starting with some maths! A ‘small’ scuba tank might contain 12l of air, compressed to 200 bar. Expand that air out to atmospheric pressure (1 bar) and that becomes 2,400l of air. Now that is dried and filtered air. There should be no water or dirt in it, just clean air.

Air might not feel as though it has much weight, but we only need to watch a helium balloon floating away to see that other gasses have a lower density and therefore a lower mass per litre. In fact, a litre of air actually weighs around 1.2g. So 2,400l would weigh 2,680g or almost 2.7kg. And if you have a 15l tank or fill it above 200 bar, then that weight goes up.

Of course, use 75% of that air on a dive and you use 75% of that weight. So yes, during a dive the weight of your tank does go down – potentially by around 2kg (more if you run empty!).

What does this mean when you are diving? Well carrying the tank after the dive is going to be a lot easier, but that is not really an issue. What is an issue and a serious one is your buoyancy. If your weight drops by 2kg to 3kg during the course of the dive, have you allowed for that in your pre dive kitting up?

The attributes contributing to your positive buoyancy are still all there, but those contributing to your negative buoyancy are diminished. If you have not loaded with the correct amount of lead before the dive you may slowly find that towards the end of the dive you are carrying less and less air in your BCD and struggling to stay level.

Don’t forget that your buoyancy also increases as you ascend as the pressure on your exposure suit is reduced. The small bubbles within it that are being compressed at depth expand, increasing your buoyancy. As you start to surface carrying less air in the tank and a more buoyant suit, you could be in trouble.

At worst, you might find that you cannot stay level for your safety stop or are fighting so much to stay level that you over exert yourself, possibly causing additional risks and maybe finishing off the remaining air quicker than you planned.

So yes, a scuba tank is certainly heavier at the start of the dive when it is full of air and you must take care to ensure that you allow for this when selecting your weights.

                          

Tip 1 – Learn with someone you can depend on
Having scuba dived for many years I have used a lot of dive centres and met various staff and instructors at these. Some of these I got to know really well and liked all of the staff. There was a feeling of trust and responsibility. I would recommend these people straight away to any other diver going near to that region.

On the other hand some dive outfits have not got my trust at all and in the worst case having spoken to the staff I walked out without booking a dive, never to return. I got bad feelings at those places.

And the problem is these people can be responsible for your life! They are taking you somewhere you don’t know, lending you equipment that they have serviced and maintained and are the ones picking you out of the water at the end of it.

Ask around at dive clubs, read independent dive reviews and anything else that you can do to check up on the dive centre before you commit to learning with them.

Tip 2 – Don’t rush purchases
It is tempting to rush out and buy lots of the gear as soon as you can. But don’t. There is nothing wrong with dive centre gear (if you have checked their reviews…) so use theirs for a while and get to learn your style of diving.

You might suddenly decide that cold water diving is for you and need suitable equipment. Or you might decide just to become a holiday diver and the cost of getting the diving gear serviced every year before your two weeks away is more than the cost of hiring the gear.

There is one exception. It is well worth buying your own mask and snorkel and maybe even fins (and boots if they are open heel fins). Why? Well once you get into your diving you might want to try snorkeling and by having your own basics you can use it then. And they aren’t that expensive if you need to replace them.

Tip 3 – Just relax and go with the flow
Never panic or rush in your diving. Always remember that it is a hobby to be enjoyed and there are some fantastic experiences to be had under the water.

So relax and plan your diver training – find somewhere good tyo train with. Then relax during the training and make sure that you enjoy it and listen carefully – this way you will learn more. And when you finally enter the water, relax and enjoy the feeling of weightlessness that comes from diving – this way your air will last longer.

                          

The purpose of a wetsuit
To choose a wetsuit for scuba diving you must first understand how it works.

Basically, it limits the amount of cold water that is in contact with your body. Water steals the body of its heat very quickly, much quicker than air. Jump into water at 20 celsius and you will feel cold, yet walk around in a room at the same temperature and you do not feel cold.

And a wetsuit does this in a very basic way – it does not stop the water coming into contact with your skin (which would be a dry suit), it just slows down the movement of that water. By wearing a wetsuit when you enter the water it will quite quickly fill with cold water, but that water becomes “trapped” inside the wetsuit. This allows your body to heat up the water and this layer of water becomes another insulating layer.

Of course, leave the water and that layer of water flushes out, go back in and you start again with warming that layer of water. And if you do not choose your wetsuit carefully, then this “flushing” action can be taking place whilst you are diving, which reduces the effectiveness of the suit.

Qualities of a wetsuit for scuba diving
So we have several qualities we want from a scuba diving wetsuit:

1) It must reduce flushing
2) It must be comfortable and allow the correct movements
3) It must be relevant to the water temperature we are diving in.

Reducing flushing
Water enters / leaves the wetsuit through the ankles, cuffs, the neck and any zip areas. So whilst these need to be loose enough to put on the suit and to be comfortable for wearing for long periods (e.g. the boat journey on a small and crowded rib and the hour long dive), they need to be tight enough when you try it on to reduce the loss of water.

Comfort and movements
Not all wet suits are made the same, or equal. Pick one specifically for scuba diving, not any other sport, so that it allows you the required movements that you will need to undertake. This can include walking (fully kitted) into and out of the sea, as well as easy swimming.

Suitable for the environment
In cold water you might want a suit that is 7mm thick (most insulation) and fully covers your arms and legs. You may even want a hood on the top of it for added warmth. Slightly warmer water might call for just a 5mm suit and warmer water still might allow you to wear a shortie suit, which has short arms and legs.

Which to buy? Well, it depends on how well you cope with the cold and where you intend to be diving.

                          

Lets get it straight from the start – too much water can be as bad as too little water when you are running. Either can impair your performance and both can kill at the extremes. Drinking little and often is what we want, not a full bottle at every water station we see in a race.

Sorry, warning over, but some people have taken the message of drinking enough to the extreme and over done the liquid intake. So why do we need water when we run?

Well every breath we exhale costs us some water vapour. When our body is too hot it cools us down by sweating and causing evaporation on our skin. And every calorie of energy used up needs some water to make it useful as an energy source.

If we run out of water then we cannot sweat and will overheat and we will not be able to metabolise energy. In other words, we will grind to a halt and collapse in a heap.

On the other hand if you drink too much water this might not seem a problem. But you are sweating not just water, but important salts (just see how salty your arms are after a hard run in summer). If you then drink gallons of water to replace that sweat then you are thinning your blood. The side effects feel the same as dehydration and the end result can be the same.

So it is important that when you are training to learn for yourself just how much water you really do need. This is quite simple. Remove your shirt and weight yourself (in kilograms ideally) before you go for your run and then repeat it after the run (removing the shirt again as it could be carrying extra weight in the form of sweat). For every kilogram of weight lost you have lost 1 litre of water (by “magic” 1 litre of water weighs 1 kg). If you add to that how many litres of you drank on the run, you know how many you used.

If your weight has gone up, then you have drank too much. Be very careful there! But hopefully your weight is down a little. Whilst elite athletes can cope with a lot of water loss, the rest of us can usually cope with about 2% loss of body weight. So, if you weigh 75kg at the start of the run you should be unaffected if you lose 1.5kg / 1.5 litres and weigh 73.5kg at the end of the run.

If you find yourself a lot under that 2% mark and are struggling with fatigue towards the end of the run, it might be worth increasing your drinking slightly, possible even by taking a sports drink with you.

                          

1) Be safe, be seen
Especially on dark evenings, make sure that you are wearing reflective clothing in bright colours. Even if you can only find a bright yellow hat, get it on your head. Ideally a running coat or top that is high visibility is best.

We had a run in a couple of weeks ago with another runner. It was dark, although there was street lighting about and about 20 of us were taking part in a club speed work session running around the block anti clockwise. This other runner decided to run around the block clockwise and got the fright of his life to see us all in fluorescent gear bearing down on him. Unfortunately, we had not seen him, dressed in black and with a pair of car headlights a little behind him reducing our vision.

2) Take it easy
Not every training session, or even race, has to be done at full speed. Ease off if you need to and save the effort for another day. If you think there is an injury forming or you just don’t feel like it today then why put yourself through the stress of a hard run? There is no shame, even in a race, in stopping and having a walking rest if that is what is needed.

3) Enjoy your run
Remember that you run because you enjoy it and get benefits from it. Whether you run to race faster or run to lose weight, then that is your inspiration and your choice. Find a new route and watch the people you pass by. Wear sunglasses in the summer and they won’t even know you are watching them!

4) You shoes have a life span
How long have you been running in the same pair of shoes? Are they passed their best, or brand new and doing their job? Depending on your running style and your body weight your running shoes will only last a relatively short while. And even if you are not using them a lot each week the materials that provide the cushioning are deteriorating slowly and providing you with less cushioning. If the shoes are getting passed it, go and treat yourself.

5) Running with others is easier
Join a running club and take part in their training sessions. You won’t be at the back of your group, even if you are the slowest. Just make sure that you pick the all ability sessions and then ask others of your standard which are good sessions to go to. You will have fun, make new friends and train a lot harder!

                          

Find a responsible dive centre
The first thing to do must be to research where you are going to be diving and most importantly, who you will be diving with. Look up some dive centre reviews so that whichever dive centre you choose to take you diving is one with a good reputation. Plenty of reviews from happy divers who have enjoyed diving with the centre and felt safe whilst using well maintained equipment is what you are looking for. Complaints about any one of these should be seen as a warning against using that centre and hopefully you can find somewhere else.

Health and fitness
As for your health and fitness, there is not really a lot of training to do. There is a lot of heavy equipment to be carrying about, but not that heavy that you need to be off and practising the weights. As long as you are in reasonable fitness and can pass a doctor’s medical then your health is probably sufficient. If you do need to work on any aspect of fitness, then your doctor should be able to advise you when you get your checkup.

Know what to expect
If you are traveling to a new area, or have never dived before, then it is always useful to know what to expect. Are there some fantastic rays or other large fish in the area? Is it known for deep wreck diving or shallow reef dives? By researching your proposed destination before you go you will know what to expect. This will allow you to book some dives when you arrive and when other divers are talking about seeing Barracuda or whatever on the dive, you will hopefully have been looking out for them and recognised them.

The easiest way of doing this is to just visit a few local dive centres’ websites and look over their reviews of dive sites and their picture galleries. There is a wealth of information to be had!

Know the environment
What water temperature will you be diving in? Will you need a 5mm shortie ir a 7mm full suit? Is night diving an option? Will you be boat diving, jumping off a pier or entering the water from a beach? They all sound trivial questions but they help you to choose your gear to take if that is relevant, or the gear to choose from the hire range if that is what you are doing. Also, if you find that the area specialises in a certain type of diving, such as drift dives, then you can plan if you want to take part and base your arrangements around that.

                          

It is very simple to get started scuba diving. You do not need to buy any equipment, although many divers will buy their own mask, fins and snorkel to learn with as they are relatively inexpensive and it is good to use your own if you can. But in short, you just take the course and then you are sorted.

So, where are you taking the course and what course? Well around the world most people will learn with PADI, but there are other organisations, the biggest of which is BSAC. Most people wanting to dive abroad will learn with PADI as it is recognised everywhere. But, if you are wanting to dive at home with a club then a local organisation (BSAC in the UK) might provide a better opportunity. Their qualifications are generally accepted as well.

If you have decided to learn the PADI way then you have three basic options:

1) Learn to dive at home, which can be very cold if you are not lucky enough to live somewhere warm.

2) Learn to dive on holiday, which can eat into your holiday time (it is about a 4 day course)

3) Split the education to study the education side and the pool side at home, then do the open water dives and the final exam somewhere warmer (called a referral).

So, who will you learn with? Well once you have decided where to learn, search for some dive centres that can provide suitable training. Then look for some reviews of these dive centers and see what other people have said about their experiences. Make sure that the reviews are favourable and that divers have enjoyed their experiences and felt safe.

Then you can book your course with whoever you have chosen and researched and ask them about the basic materials. A lot will supply the materials for you when you first turn up, but with more and more interactive methods for studying the course this may be optional where you are learning and you might be able to buy the manuals on DVD before you start to learn. This allows you time to study the course, should you wish to, before you start your course. You can then start your diver’s education in the knowledge that you know what is coming up.

The thing to remember though is that diving is not something that you can study for 4 days and then know everything about. Until you are comfortable in the water and experienced you will not get the full experience from the sport. For this reason many see the Open Water course not as the way to learn, but the first stage of learning. You can then follow it up with the Advanced Open Water course, various speciality courses and a whole lot more of different training courses.

                          

First of all, if you do see a shark when you are scuba diving then think yourself very lucky. If you have a camera then even better – get some photos of the animal and enjoy the experience.

There is a huge problem with shark encounters in the water – they are hyped up. Yes, on occasion people are attacked and injured, or even killed, in shark attacks. On very rare occasions these attacks are against divers. But the human race kills far more sharks each year then the number of people killed by sharks each year.

Encountering a shark whilst scuba diving should be a thrill. It is something to talk about with your diver friends and your mates down the pub. Don’t panic, but then don’t be silly.

Sadly, for me, I have only had limited shark encounters. And each time the sharks were so small that they were certainly not a threat to humans. However, I have also dived in waters with Hammerheads in the vicinity and see their fins when leaving the area.

So apart from photographing the sharks for posterity, what should you do? Well a lot depends on what species of sharks there are in the area. Your dive master will be able to tell you what there is about and if there are any specific precautions to take.

But on the whole, and as in my experience, although the sharks might be in the area they are shy and retiring and will generally try their best to keep away from divers. And the bigger and more fearsome the species, the more they will keep away. They are shy beasts, more worried about their own safety then they want to eat us. They want to attack easy prey – injured animals and those lounging on the surface of the water. Potential prey that can see them, fight back and maybe injur the shark are almost usually no longer prey.

So this gives us the basics if you are worried about sharks approaching you.

First, avoid floating on the surface and looking like a dead animal. If it is time to leave the water then keep your mask on and watch what is happening beneath you.

Make sure that at least one of your party is watching the sharks and turn to face them if they are start to approach you. By looking large and willing to defend yourself then you are likely to avoid a further encounter.

Of course, there are certain sharks with reputations for being more aggressive. But unless these are in the area and active, you are unlikely to really be bothered. It is normally only those shark feeding that really get up close and personal to the sharks.

                          

Getting certified as a scuba diver is not intended as being a complicated task. There is a simple swimming test, some exercises to learn and complete in both the pool and an ‘open water’ environment and a final exam.

It sounds difficult, but it is not. The minimum age for learning scuba diving is quite young and these youngsters are more than capable of managing to learn the skills and the information needed. So don’t worry about it too much! But to get you going, here are three useful tips.

Tip 1 – why restrict your education to the course?
When, many years ago, I first got certified as a scuba diver, the internet was still in its infancy, but it was there. And I used the internet to read up on what was involved. I read more about the equipment and how it worked, the hand signals, how to use the various charts and a lot of the theory.

Because I took the research at my own pace and read around the subjects it was very interesting and gave me an understanding of everything that was involved. In the end, for my end of course exam I managed a 100% mark.

Tip 2 – relax and enjoy it
I’ve already said that the course is not that mentally taxing. It is designed for all to enjoy and experience. The main thing is to relax and enjoy what you are about to experience. Your first dive could be your first experience of the ‘weightlessness’ that divers can experience and the joys of swimming with the fish, without them swimming away from you, can be very enjoyable.

Many years later I still remember the details of my first dives and look back on them fondly. By relaxing and enjoying the whole course you will take in the information far easier, manage the exercises with ease and get the full benefit from your 4 practice dives. When you are taking part in the drills, and if anything does go wrong in those first dives, then by being relaxed you will handle the situation properly.

Tip 3 – be careful who you learn with
It is almost a shame to leave this tip to last, but it is absolutely vital. Do not just walk up to the nearest dive centre when you are on holiday and book a diving course there. Before you even travel, look out for some dive centre reviews and make sure that the place you have chosen gets some good reviews. If you are learning on impulse, then at least take a try dive with them before you sign up.

You want to find an instructor that is friendly and very safe. Anything other than that could be a disaster for the enjoyment of your learning.

                          

Regulators / Regs – this is what you use to get the air from your tank into your mouth. They regulate the high pressure air in your tank, reducing it to the same pressure as the water that is around you, so that breathing is easy.

First stage (regulator) – this is the part of the regulator that attaches to the tank, reducing the air to the safe pressure for the hoses.

Second stage (regulator) – this is the part that goes in your mouth, the second part of reducing the air pressure to the correct pressure.

BCD / Buoyancy Control Device / Stab jacket – not some sort of fight protection, but a device that you wear (as a jacket) that helps you stabilise your buoyancy in the water. With many pockets to store other bits of gear in, you add air into it to increase buoyancy and remove air to reduce buoyancy in the quest for neutral buoyancy.

Wings
An alternative to a BCD, its shape means that the air pockets are either side of your tank (as opposed to surrounding you in a BCD). It gives a more face down swimming aspect, which is brilliant for diving, but can be a problem for the less experienced diver on the surface.

Buoyancy – are you floating, sinking, or swimming level? An object that is positively buoyant will float, one that is negatively buoyant will sink whilst a neutral one will hover in the water, which is what we as divers desire.

Gauges – how much air have you got left? Your gauges will tell you just that. A simple look will tell you how many bars of air you have remaining. You start off with about 200 (maybe even 300) bars and every breath slowly reduces the content of your air cylinder until it is empty.

Tank – contrary to many TV programs, the tank that we carry on our backs contains nothing more than normal atmospheric air, that has been dried. It is not an oxygen tank – if you breathed pure oxygen deeper than about 6 metres you would kill yourself. Unless you are trained to use Nitrox or other mixes, you are just carrying normal air.

Open water – you may here about Open Water certification, open water training, open water dives and so on. These are all just referring to bodies of water other than the confines of swimming pools. From quarries to oceans, they are all open water. And an Open Water certification is the basic PADI certification that allows you to dive without being accompanied by an instructor.

PADI / BSAC – these are two of the main diving organisations, but there are plenty more. They provide reference material, set the syllabuses for courses and monitor the dive centres.

                          

What is neutral buoyancy?
Neutral buoyancy is the aim of the diver. When you look at the water, life jackets and similar objects are positively buoyant – they are trying to float on the water’s surface, whereas stones are negatively buoyant – placed on the surface they will sink.

But as a diver, as with fish, we want to be able to leave the surface, without having to crawl along the floor. We want to be able to control our depth in the water and for this we need to be neither floating nor sinking – we need to achieve neutral buoyancy.

The advantages of neutral buoyancy
If we do not achieve this neutrality, then we are either trying to float or to sink. Whilst at the end of the dive floating on the surface is desired, for the rest of it we want to be exactly where we put ourselves.

If we are slightly positively or negatively buoyant, then we have to put in extra effort to maintain our position in the water. We are either constantly swimming up or down. Watch a healthy fish in a tank and you will see that they swim level when they want to be level, but swim up or down to change depth. That is what we want to achieve.

More than saving effort, by having total buoyancy control we are not bouncing around. Such bouncing messes about with the nitrogen in our blood streams and increases the risk of the bends. At the extreme, positive buoyancy can send us hurtling to the surface (I’ve seen it happen), or tumbling to the bottom of the water. Neither is desired.

The tools at hand
We have three tools at hand to maintain our buoyancy:

1) Weights, plus the weight of our equipment to counteract our positively buoyant body and the equipment we are carrying (a wetsuit is positively buoyant).

2) A buoyancy control device (BCD), wing or similar to add air to our equipment during a dive to increase buoyancy.

3) Our lungs, which compliment the BCD with fine adjustments.

Using weights to adjust buoyancy
At the end of the dive our overall weight is at a minimum. We have used up most of our air and reduced the weight of the tank, whilst the wet suit and our own body are making us positively buoyant. Therefore, we carry weights to make us negatively buoyant.

A BCD
As we dive deeper the air spaces, including the air trapped in our wet suit / dry suit, are compressed. This reduces our buoyancy the deeper we dive. Therefore we add a little air to the BCD as we dive deeper, remembering to release it as we ascend.

You just need to watch carefully how you are diving. If you are finding yourself swimming downwards then you are fighting the positive buoyancy and need to release some air, whilst if you are swimming ever so slightly upwards then you are fighting the sinking feeling and need to add air. Just a couple of bursts of air in or out will do, then wait. It will take a few seconds for the air to redistribute and you to either correct your manner of swimming, or find that you have under / over corrected.

Lungs
Excellent for fine tuning. If you want to increase your buoyancy slightly, just take deeper breaths and don’t let so much out. You can do the opposite if you find yourself trying to float. Especially useful if you need a temporary fix, e.g. to swim over or under a rock.

                          

Staying warm whilst diving is not just about the enjoyment factor. Get too cold and start shivering and you then start eating through your air a lot quicker. Your endurance will drop and you will remember the dive as a bad, short dive rather than another enjoyable experience.

So, what can you do? Well the basic answer is to wear an exposure suit that is appropriate to the water temperature and how well you handle the cold. In water that is not too cold, a 5mm shortie wetsuit may be enough to keep you comfortable throughout the dive.

But, if the dive is slightly colder then you might need more protection and for that you will be looking at thicker and more covering wetsuits. A lot of areas will supply 5mm full length wetsuits for their divers, usually in one piece suits. Because they cover more of your body they keep you warmer.

However, that is only true with a well fitting suit. If the cuffs, ankles, neck or zip area allow a lot of water in and out then the protection is lost. These cuffs, ankles and neck should be snug fitting, although not so tight as to cause you discomfort in the water. By preventing the flow of water in and out of the suit (“flushing”) you are helping to keep yourself a lot warmer.

If you want a little bit more warmth then making sure you are using open heeled fins combined with wetsuit boots are a lot warmer then closed heel, where your foot is exposed directly to the water.

Warmer than the 5mm suit is the 7mm suit. If you are finding that the thinner suit is not keeping you warm then just ask if there are any 7mm suits available. The thicker material should provide a little extra insulation and keep you warmer.

On top of this you can also buy yourself a pair of wetsuit gloves and a separate hood. I have gloves in both 5mm and 7mm, depending on how cold the water is. The thinner gloves are easier to handle gear in so they are my preference, but if the water is very cold then the 7mm gloves provide the protection that I want. Again, gloves and hood should be well fitting and not allow a lot of water to flush through them. Water flushing through them means they aren’t doing their job.

Lastly, if you are going to colder water then you need to look at a semi-dry or even a dry suit. These have better cuffs and seals and should not allow in any water (or very little water in the case of a semi dry). And with a a full dry suit you can also wear a range of thermals underneath them. From basic thermal underwear to purpose made thinsulate suits to keep you snug and warm!

                          

Why cleaning scuba gear is vital.
You might think that equipment that is made specifically for use deep underwater would not be affected by emerging it in salt water, but salt water is very corrosive and whilst the equipment can safely survive its immersion whilst in use, leaving salt water on the equipment between dives can cause a lot of damage, shorten the life span of gear and even cause its untimely failure.

When sea water dries on your scuba gear it evaporates off. But only the actual fresh water component evaporates. Salt, and other dissolved minerals, stays on the surface of the valuable gear and even after the water from just one dive has dried off you will see a white residue in the places where the water pooled.

The damage that can be done
Salt water left on your mask can damage the silicone seal that runs around the mask and forms the tight seal around your face. If this is damaged it can crack or become stiff. Either of these will stop the skirt from doing its job and you will know about it because the mask will leak.

Your regulator is not immune either. Dried on salt can damage the finer workings of the regulator or even block parts of it from working. And if there is salt water in the air pockets inside your BCD these too can corrode and fail, leaving you unable to inflate it.

The problem continues in that some of the materials are also damaged by long term exposure to sunlight and excess heat. Never leave your mask out in the sun to dry, that too can damage the skirt.

Some tips for cleaning your gear.

1) As soon as possible after the dive immerse and rinse all of your gear in a bath of cold water. This is probably going to be a shared bath of water, so not fully clean, but if you are diving later that day or the next day then it should be clean enough.

2) When not diving for any length of time and certainly after a run of dives on holiday, wash your gear in a shower to make sure that every trace of dissolved materials are removed.

3) Hang up your gear to dry, but somewhere out of the direct sun and make sure that it is somewhere overlooked – you do not want someone stealing the equipment.

4) Be careful when rinsing and bathing regulators not to get water inside of them – keep your fingers off that purge button! If water enters them then it can run into the hose and cause problems there.

5) If you can, don’t use the manual inflator / dump to release air from your BCD as this allows water back in. The dump valves are usually much less likely to allow the entry of water. But drain the water that does get in after every dive.

                          

Hopefully, if you are running a marathon in just 3 months then you will have at the very least some sort of running base behind you. Maybe you have entered the odd 5k, maybe even a 10k, race. Better still you have recently completed a half marathon.

But, to be reading a 3 month training plan then I am guessing that at most you will have prepared yourself for a 10k event, and probably much less than that.

Starting at the end, there is the often talked about taper. Usually quoted as 3 weeks, if you start training 3 months before the race and then include a 3 week taper, you are reducing your training to 9 or 10 weeks.

However, that 3 week taper is for those who have trained hard over a year or so and really need a lot of time to recover from the training. If you are just starting your training 3 months before the race you can forget that long taper! All that you need instead is 1 week, maybe 10 days, before the race when you ease off.

So that now gives us an indicator of how much solid training time we have to work with. If 3 months is 13 weeks and the last week is a taper, we have 12 weeks of training.

Before you go into meltdown and panic, remember that a slow build up and consistency of training is what is needed. Rushing into a 6 mile run on the first week of training is a recipe for disaster. Reading about marathon runners doing 80 – 100 miles per week in training is also bad news. You can’t do that without months, even years, of training behind you.

Let’s get realistic, what do you want to do and what can you achieve? In short, probably to get around the 26.2 miles and finish not feeling too bad. Forget about setting yourself a time target, just get around this time and next year try again with more training.

A gradual build up is essential. If you have not ran before then in week 1 go out on 3 days (leave a day’s break between each) and run for just 10 minutes each time. Then just slowly build up from there. Week 2 will be 15 minute runs and week 3 you will do 20 minutes runs. Yes, at this rate you will never make it. Don’t worry, we have a plan.

From week 4 you increase your long run by 10 minutes per run per week, so that week you are running for 30 minutes each time. Week 5 is a magic week – the 2nd & 3rd run reach 40 minutes and from now on get no longer! We concentrate here on the one long run each week.

Obviously, if you have some recent running experience then your weekly runs might already be a couple of miles each. In that case, just increase the distance of the long run the same way as I have already described, but starting from where you are now.

Ideally in a full marathon training schedule you will run up to 20 miles per week, but with only 12 weeks of preparation, you are not going to get there! But after 12 weeks of this increase you will find that you are running / walking for just under 2 hours. If you want, on the last 2 weeks increase the run by 15 minutes so that your last run is a 2 hour run. It feels great to say you did it!

And what pace for all of this? Well start slow and stay slow! On those first few runs learn what is a comfortable pace by running slower than you feel you should. If at the end of the run you have plenty left in you, increase the pace slightly next time.

                          

First of all, scuba diving can be a dangerous sport to undertake, So, for that reason you will swim with a buddy. This will usually either be a diver that you know, for example your regular partner, or if you have turned up to an organised diver on your own, then you will usually buddy up with someone of a similar ability. You and your buddy dive together and provide a backup for each other if there are any problems.

You will also most likely learn to dive with PADI. This is an organisation of instructors that arranges and quality controls courses and ongoing training of divers. They do tend to encourage divers to be taking courses forever, but certainly more than the basic course is required to become a competent diver.

When you breath underwater you will use a regulator, that you hold gently in your mouth. The problem is that the cylinder on your back holds hundreds of litres of compressed air at very high pressure. If you breathed that directly your could burst your lungs. So the regulator reduces the air pressure to the same as the water pressure around you, making it not only safe, but also very easy to breath underwater.

You will also attach some type of buoyancy aid to your air cylinder. BCD, stab jacket, wing or whatever you like to call it (a ‘wing’ is a special variant of these), the purpose of these devices is to help you control neutral buoyancy underwater. You do not want to be fighting to swim down (which you would if you were positively buoyant), nor having to fight to swim to the surface (negatively buoyant). By controlling the amount of air in the buoyancy aid you can achieve neutral buoyancy and the feeling of hovering in the water.

And as water is not always the warmest of media to spend time in, you will probably also wear an exposure suit. From a dry suit, to a semi-dry to a wet suit, these prevent or reduce the amount of cold water touching your skin. This keeps you a lot warmer and means that you can spend longer underwarer without feeling cold and uncomfortable.

Lastly, you might be undertaking safety stops. These are because as you are breathing air under pressure under water you are building up tiny nitrogen bubbles in your blood and you want to release them slowly as you ascend.