New Jersey Scuba Diving

Human lungs are designed to extract the oxygen we need from air - a mixture of roughly 21% oxygen and 79% nitrogen, at a pressure of one atmosphere ( about 14.7 psia.) As you dive deeper and longer while breathing air, the increased pressure causes ever-greater amounts of both gases to dissolve in your blood and tissues. One would expect that eventually, such elevated concentrations would become troublesome, and indeed that is the case. As it turns out, nitrogen, with its greater concentration in the air, is the first gas to become a problem during a dive to recreational depths ( <130 ft. )

This problem is that of "off-gassing", or decreasing the concentration of dissolved nitrogen in the body at a rate that does not cause bubbles of the gas to form in the tissues and blood, the condition commonly known as the bends. One way to delay the onset of this problem is to decrease the concentration of nitrogen in the breathing gas, and the easiest way to do this is simply by increasing the concentration of oxygen. The resulting mixture is typically known as Enriched Air Nitrox and has become a staple in the diving community.

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Here is a description of recreational dive planning. The purpose here is to demonstrate basic dive planning and use of Dive Tables for non-divers who are interested in becoming certified but are worried about the complexities and math involved. Learning to use dive tables is usually the single most daunting classroom task for a student diver. It's really not all that hard.

The purpose of dive planning is to manage the Nitrogen gas that is absorbed into the tissues of your body while breathing air at higher-than-normal pressures underwater. If you absorb too much Nitrogen at depth and then ascend to normal atmospheric pressure, the gas will form bubbles in your blood and tissues. This is called Decompression Sickness, commonly known as "the bends." Decompression Sickness can vary in severity from barely noticeable to fatal, depending on your dive profile and other factors. The goal of no-decompression dive planning is to plan your dives in advance so that under no circumstances* can ascending to the surface result in Decompression Sickness.

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Here are a series of excellent articles regarding the buddy system, reproduced from their original sources before they "wink out", as so much good web content does. With regard to the Buddy System that is so entrenched in dive training, these articles are all negative. I feel no need to present counter-balancing positive arguments since you can get that from any dive instructor with any of the major certifying organizations.

When you first get certified, you will have had the buddy system drilled into you. At this point, you still have basically no idea what you are doing, so just do it that way. A lot of what is in the basic open-water certification is silly and even unnecessary, but it won't get you killed.

As a newly-certified diver, you are a danger to yourself and everyone around you. Be glad that any operator will take you out, and don't rock the boat. If they want you to dive with a buddy, dive with a buddy. As crew, I've spent numerous dives paired up with newbies to make sure they have a good time and get back to the boat OK. Shallow-water shore diving can get very tricky, and things can go very wrong, and if you are not experienced, having a buddy can be a lifesaver.

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