NOTE: Free essay sample provided on this page should be used for references or sample purposes only. The sample essay is available to anyone, so any direct quoting without mentioning the source will be considered plagiarism by schools, colleges and universities that use plagiarism detection software. To get a completely brand-new, plagiarism-free essay, please use our essay writing service.
One click instant price quote
... ces in our bodies. As previously mentioned, pressure increases at a rate of one atmosphere (ATM) for each additional 33 feet of depth underwater. The total pressure is twice as great at 33 feet than at the surface, three times as great at 66 feet, and so on. This pressure pushes in on flexible air spaces, compressing them and reducing their volume. The reduction of the volume of the air spaces is proportional to the amount of pressure placed upon it.
When the total pressure doubles, the air volume is halved. When the pressure triples, the volume is reduced to one third, and so on (Tillman, 40). The density of air in the air spaces is also affected by pressure. As the volume of the air spaces is reduced due to compression, the density of the air increases as it is squeezed into a smaller place. No air is lost; it is simply compressed. Air density is also proportional to pressure, so that when the total pressure is doubled, the air density is doubled.
When the pressure is tripled the air density triples and so on. To maintain an air space as its original volume when pressure is increased, more air must be added to the space. This is the concept of pressure equalization, and the amount of air that must be added is proportional to the pressure increased. Air within an airspace expands as pressure is reduced. If no air has been added to the air space, the air will simply expand to fill the original volume of the air space upon reaching the surface (Ketels, 76). If air has been added to an air space to equalize the pressure, this air will expand as pressure is reduced during ascent.
The amount of expansion is again proportional to the pressure. In an open container, such as the bucket, the expanding air will simply bubble out of the opening, maintaining it original volume during ascent. In a closed flexible container, however, the volume will increase as the pressure is reduced. If the volume exceeds the capacity of the container, the container may be ruptured by the expanding air (Cramer, 51).
Now let's take a look at how the relationship between pressure volume and density affect a diver while diving. Previously it has been mentioned that air spaces are effected by changes in pressure. The air spaces that a diver is concerned about are both the natural ones in your body and those artificially created by wearing diving equipment. The air spaces within a diver's body that are most obviously affected by increasing pressure are found in the ears and sinuses. The artificial air spaces most affected by increasing pressure is the one created by a divers mask. During descent, water pressure increases and pushes in your body's air spaces, compressing them.
If pressure within these air spaces is not kept in balance with this increasing water pressure, the sensation of pressure builds, becoming uncomfortable and possibly even painful as the diver continues to descend. This sensation is the result of a squeeze on the air spaces. A squeeze is not only a scuba phenomena but may also be experienced in a swimmers ears when diving to the bottom of a swimming pool. A squeeze, then is a pressure imbalance resulting in a pain or discomfort in a bodies air space. In this situation, the imbalance is such that the pressure outside the air space is greater than the pressure inside (Ketels, 76 - 77). Squeezes are possible in several places: ears, sinuses, teeth, lungs and ones mask.
Fortunately, divers can easily avoid all these squeezes. To avoid discomfort, pressure inside an air space must always equal the water pressure outside the air spaces. This is accomplished by adding air to the air spaces during descent, before discomfort occurs. This is called equalization. Compared to the ear and sinus air spaces, the lungs are large and flexible.
As a scuba diver, one automatically equalizes the pressure in the lungs by continuously breathing from the scuba equipment. When you skin dive, holding ones breath, the lungs can be compressed with no consequence as long as they are filled with air when one begins to descent. The lungs will be reduced in volume during decent and will re-expand during ascent to nearly the original volume when one reaches the surface (some of the air from the lungs is used to equalize the other body air spaces) (Ketels, 78). In a healthy diver, blocking the nose and attempting to gently blow through it with the mouth closed will direct air into the ear and sinus air spaces. Swallowing and wiggling the jaw from side to side may be an effective equalization technique. Some divers even attempt a combination of the previous two methods.
As mentioned previously along with squeezes, the lungs experience no harmful effects from the changes in pressure when holding ones breath while skin diving. At the start of the skin dive, one takes a breath and descends; the increasing water pressure compresses the air in the lungs. During ascent, the air re-expands so that when reaching the surface, the lungs return to their original volume (Ketels, 78). When scuba diving, however, the situation is different. Scuba equipment allows one to breathe under water by automatically delivering the air at a pressure equal to the surrounding water pressure. This means the lungs will be at their normal volume while at depth, full of air that will expand on ascent (Cramer, 51).
If a diver breaths normally, keeping the airway to you lungs open, the expanding air escapes during ascent and your lungs remain at their normal volume. But, by holding ones breath and then blocking the airway while ascending the lungs would over expand, much like the sealed bag. Expanding air can cause lung over-pressurization (lung rupture), the most serious injury that can occur to a diver. The most important rule in scuba diving is to breath continuously and never hold your Breath.
Lung rupture will occur unless pressure is continuously equalized by breathing normally at all times (Cramer, 52). Other physical Phenomena's As an air-breathing creature, we have evolved to live on land. Above the water, we see, hear and move about in a familiar and comfortable manner that seems normal because we have adapted to an air environment. Under water, though, one enters a new world, where seeing, hearing, staying warm and moving are different. This is because water is 800 times more dense than air, affecting light, sound and heat in ways that we aren't used to.
Sight seeing is a big part of what diving is all about. One dives for numerous reasons. A primary purpose is to see new environments, aquatic life and natural phenomena. Since underwater sight seeing is important, like buying a new camera, one must learn, how. Therefor when diving, one must know how the liquid environment affects vision. To see clearly under water, a ma...
Free research essays on topics related to: spaces, scuba diving, volume, water pressure, total pressure
Research essay sample on Scuba Diving Water Pressure
