TRAINING

The information below is presented to every group before diving as a instructional lecture with a question and answer opportunity so that every participant is comfortable with the information before ever getting in the water. If you like you are welcome to review it here.

1) Bouyancy.

Bouyancy is the upwards force created by the water on an object which displaces more water than it weighs. What this means is that if an object displaces a gallon of water which weighs about 8.5 pounds, but it weighs less than 8.5 pounds, it will float.

Imagine a gallon milk jug. If you fill it with concrete it will weigh 20 pounds but only displace 8.5 pounds of water, so it will sink. If we fll it with air it will weigh nothing, but will displace 8.5 pounds of water and it will float. If we fill it with sea water then it will weigh 8.5 pounds and will displace 8.5 pounds of water so it will not sink or float, it will be "Neutrally Bouyant".

As divers we want to be neutrally bouyant so that we don't have to swim to keep from sinking to the sea floor, and we don't want to float so that we have to swim to stay down. We want to be neutral so we stay at whatever depth we like without effort.

The human body is slightly bouyant which is why you can backfloat, we are not bouyant enough to float with our whole head out of the water, the average head weighing about 10 lbs, but we do float. This is partly due to air spaces in our bodies, like our lungs, and partly due to some of our tissues being less dense by volume than water.

So to acheive neutral bouyancy we need to carry a little weight, not much but for most people, a little. We carry this weight in the form of little sand bags filled with sand made of lead, and we carry these weights in special pockets in our harness. With the right amount of weight you will literally be weightless in the water and only the sightest effort will be able to move you in any direction you like.

Your guide will help you establish exactly how much weight you will need to be neutrally bouyant. Once you are neutrally bouyant exhaling fully will cause you to be slightly negatively bouyant and you will very slowly begin to sink. Taking a deep breath will increase the air space in your body and you will become positively bouyant and will slowly begin to float upwards. By breathing normally, slowly and calmly, you will maintain neutral bouyancy enabling you to hover in place without bumping into the rocks or corals or floating to the surface like a baloon.

2) Air Spaces -

There are several air spaces in the human body, the lungs which expand and contract, the sinuses which we breathe through when we breathe through our noses and a tiny space in the inner ear which is connected to your throat by a tiny passage called the Eustation tube.

As we go deeper into the water the pressure of the water above us compresses air, it can't compress tissue because tissue is made of water and liquids are not compressable, but it can compress air. In fact at 33' or 10 meters of depth the pressure on an object is twice what it is on the surface.

So of we take a tennis ball which on the surface has a diameter of 2 3/4" or 6.7 cm, and we take it in our pocket down 33' or 10 meters into the sea, it will shrink to half it's size or a little smaller than an egg. As we bring it back to the surface it will slowly return to it's original size. The same is true of the air spaces in our bodies.

You won't notice any pressure on your lungs because the regulator you breathe through will automatically compensate by increasing the pressure of the air you are breathing, you may however notice in your ears, just like you do when you fly in a plane or dive to the bottom of a pool. To prevent this discomfort divers learn to "equalize" or "clear" their ears.

Just like when we fly, moving your jaw forward and backwards can help to open your eustation tubes and equalize your ears. Divers use another trick called the Valsalva Maneuver which you pinch your nose and close your mouth and gently push air, like when blowing up a baloon, into your inner ears.

Every person is different, some people have no issues equalizing their ears, other people find it difficult, the important thing to remember is to equalize your ears early and frequently starting as soon as your head goes under the water. Don't wait until your ears hurt, but this time the tisue is already being squeezed and you probably will not be able to equalize your ears, so early and frequently is the best rule. If your ears begin to hurt, go up a little until they stop hurting and equalize then descend slowly again equalizing as you do.

Another air space which will become compressed is the air space in your dive mask, this is much easier and you can equalize it simply be slightly exhaling through your nose. Again, don't wait into your mask is being pushed into your face and is uncomfortable, equalize early and often.

You don't need to worry about equalizing as you come up as the air will be expanding and will simply push it's way out of the inner ear all by itself, just like it does when a plane is going up.

3) Breathing -

The breathing part is the part most people are interested in and the part of the experience you need to think the least about. You will be breathing through a device called a regulator, or technically the "Demand Valve", it was originally designed in 1838 and finally reworked into what we consider the modern scuba regulator by Jaque Cousteau and Emile Gagnan in 1942 and has been improved upon since then.

The Regulator hangs around the divers neck and will deliver as much air as the diver requires. Regardless of wheather you are breathing slowly or rapidly, deeply or shallowly, the regulator autoimatically responds to the needs of the diver. As you inhale air is supplied to you through an air line connecting you with the surface support module, and as you exhale the air escapes through vents on each side of the divers mouth.

The diver only needs to remember two things; 1) Keep the regulator in your mouth, if it's not in your mouth, you can not breathe through it. And 2) Do not hold your breath, ever. Holding your breath deprives you of oxygen, it makes you bouyant so you begin to float upward and it holds air in your lungs which needs to expand as you ascend to the surface. If you don't give this air a way to escape as it expands, you can damage your lungs. So NEVER hold your breath.

4) Clearing your mask.

While your mask is attached to your face, it is possible that the seal can be broken, some hair where the mask seals to your face, maybe you bump the mask with your hand, or you want to allow a little water into your mask to rinse fog from the glass, there are many ways that a little water can get into your mask.

To clear the water from your mask you simply need to hold the mask gently to your face by holding te mask by the sides and top applying slight pressure with the top two fingers of each hand on the upper portion of the mask at your forehead, take a deep breath through the regulator and slowly exhale through your nose while looking upward. As the mask fills with air the water in the mask will be forced out and once again the mask will be full of air.

Your guide will help each diver with this proceedure until you are comfortable with it and can take your mask off and put it back on in the water. This way you will be confident during your dive that should water get in for any reason, you can clear the mask and go on with your dive.

5) Going down and coming up.

Once everyone in your group is comfortable with their mask, weight and regulator your dive guide will slowly take the group down. Each diver will clear their ears and get comfortable with breathing underwater as the guide helps each diver with any issues until all the divers in your group are on the boattom in the sand.

When the whole group is ready the guide will lead the group on the dive, the divers will leave the bottom and follow the guide on the dive. Your guide will be on scuba and will be watching all the divers in your group.

Once the dive is complete the guide will bring the group together and they will all begin to slowly ascend as a group. Each diver ascending their air supply line hand over hand until the entire group is back at the surface support module with their heads out of the water and regulators out.

If at any point during the dive any diver wishes to return to the surface, they can signal the guide who will then instruct them to ascend along their air hose slowly to the surface and the group will wait until that diver is at the surface support module before continuing.

6) Safety -

You will be with a dive guide the entire time you are in the water. Your harness is connected to the air supply line which is also connected to the surface support module so you can not drift off or get lost and can alwasy ascend your airline to the surface where the unsinkable surface support module, the boat and boat captian are waiting

Your air is being supplied by the surface support module and you are under the speervision of the guide who is also equipped with an additional air supply source and you are never far from the surface and the boat.