Suunto Fused™ RGBM

DIvING AND YOUR BODYDiving is a great activity with thepotential for one-of-a-kind experiencesyou can only get in an aquaticenvironment. Our land-loving bodies,however, can react negatively todiving if we are not careful. Wheneveryou enter the water, be aware howyour behavior before, during andafter the dive can affect your health.Under water your body is being pushedin from all sides. This added pressurechanges how your body functions.Some of the changes you notice,like with breathing. Other changesyou may not immediately feel, but theeffects can cause serious damage toyour body, and even lead to death.The pressure change under water canaffect sensitive areas such as your earsand sinuses. Discomfort in the earswhen taking off in an airplane is alsofelt just diving down to the bottom ofa pool that is three meters deep.But the most significant impact is onyour circulatory and respiratory systems.These need to be taken seriouslyas they can lead to major healthrisks. To understand and avoid theserisks, we need to first have a look atthe world of gases.10 metersCopyright © 2012 by Suunto Oy. All rights reserved.Ambient pressureAmbient pressure increases much fasterunderwater because water is denser thanair. Ten meters down is already twice thepressure at the surface.20 metersA WORLD OF GASESIn the physical world, we are mostfamiliar with three phases of matter– gas, liquid and solid. Certain elementsand compounds are naturallyin one state or the other at a giventemperature.Typically we think of water beingmerely a liquid, but that is only truefor pure H 2O (between 0-100 C). Bothliquids and solids naturally containgas. The oxygen dissolved in water,for example, is what allows fish andother aquatic life to breathe.Our bodies are also full of dissolvedgases. Some of them, like oxygen,our bodies actively use. Other socalledinert gases like nitrogen andhelium, are not used by our bodies,but are carried in blood and tissuesnonetheless.It is these gases that can cause somuch trouble for divers. Even oxygenwhich our bodies thrive on at surfacepressures can become toxic undercertain conditions.Nitrogen and helium are the mainculprits when we look at the numberone risk divers are concerned about:decompression sickness (DCS).Gas exchange in alveoliWhen air enters the lungs, it goes througha maze of smaller and smaller tubes untilit reaches tiny sacs called alveoli. Woveninto the walls of these sacks are very fine,almost transparent, capillaries.Suunto Fused RGBM www.suunto.com 3