SUMMARY
- Divers breathe air from tanks. When the diver exhales, there is a mixture of nitrogen and oxygen in the lungs. The gas exchange rate (how much oxygen the body needs per minute) at depth is low. Therefore, breathing surface air into a diving suit or closed circuit rebreather will not increase the diver’s metabolic rate. Breathing compressed air into the suit or rebreather will only worsen performance because it increases oxygen consumption and eliminates improvised equipment that allows divers to consume up to 35 times less oxygen than they would on the surface.
- Breathing pure compressed air or even helium can increase metabolic rate by as much as 30%. This increase in metabolism will cause increased blood flow and heat production, which can lead to hyperventilation without a proper counterbalance of nitrogen in breathing gas mixture at depth. Hyperventilation causes decompression illness (DCSI). DCSI is caused by an imbalance between nitrogen concentration and pressure during ascent, which produces bubbles in extravascular tissue spaces such as blood vessels, coronary arteries and lung alveoli. The bubbles are eliminated slowly by gravity when breathing stops but can cause injury including severe pain, kidney failure and heart failure if not treated quickly with recompression therapy under medical supervision. Divers should be familiar with NBC’s recommendations for preventing DCSI for dive planning purposes: https://www.nbc4i.com/diving-safely/diving-disorders-and-prevention/embar…
- Inhalation rates at depth are high enough that breathing pure nitrox mixture while scuba diving is unnecessary unless one dives deep very often or goes to high altitude where there is little available nitrogen in atmospheric air or altitudes above 18′. With pure oxygen breathing gas mixes containing more than 20% oxygen
How to read them?
When you’re reading dive tables, it’s important to follow some basic guidelines. The first rule is that the dive table must be read in order. Your dive computer will provide the necessary information for any given depth and time interval, but it isn’t a good idea to skip around on the tables or try to find your own path through them.
The second guideline is this: keep the table at eye level when you are reading from it! It’s not good practice to place your hands on either side of a paper document as you’re trying to read; instead, use two hands (or one hand and one foot) for support underneath the document itself. If needed, use something like an old book beneath it as well – just make sure that whatever object(s) are providing support are flat against the surface so that nothing moves while diving down into water depths with increasing pressure on their bodies!
Dive tables
Dive tables are used to calculate how long you can stay underwater based on your age, weight, and depth. They were developed by the US Navy in the 1950s; later, other agencies adopted them for use in their own diving operations.
How to read dive tables? Diving tables are based on a number of factors, including your weight and depth. The calculations involved with using dive tables require some math skills—if you’re unsure about your ability to complete these equations accurately, it’s best to consult an expert before relying on dive table figures for safety reasons (i.e., if this is something that will affect your life or health).
Understanding the dive tables
Dive tables are used to calculate the correct decompression schedule for a given depth, time at that depth and breathing mix (gas). Dive tables were developed by decompression experts at Naval Experimental Diving Unit in 1960s and 1970s. The dive computer was not invented until late 1980s. Therefore, dive tables were the only tool available for recreational divers until then.
The single most important thing to understand about dive tables is that they are not meant to be used alone: they must be supplemented with some other means of monitoring your dive profile (such as a depth gauge) or else it’s possible for you to get dangerously out of range.
Reading the dive tables
In order to get a basic understanding of how to read dive tables, let’s first take a look at what they are.
Dive tables are used by divers when calculating their decompression times after a dive. They can also be used to calculate the gas consumption rate for breathing air or nitrox mixes. Dive tables tell you how long you need to spend on each depth before surfacing, based on your depth and exposure time. Knowing this information is critical because it helps you plan your dive and make sure that there is enough time before reaching the surface for all gases in your body to be eliminated safely.
How to read dive tables? It’s very important that you understand what the dive tables do in order for them to be useful in planning your dives correctly!
Using dive tables
Dive tables are the most popular method of calculating decompression schedules. Dive tables provide a fairly simple way to calculate your decompression time, but they’re limited in their accuracy because they don’t take into account how much oxygen you’ve consumed during a dive.
To use dive tables, find the depth of your dive on the left side of the table and then follow it across until you reach your bottom time (time spent at depth). The number in between those two points is your decompression stop time. If you stop at 5 feet for 10 minutes before surfacing from an 80-foot dive, then 5 feet = 0:10 and 80 ft = x:xx where “x” represents your actual stop time (in minutes).
You can use dive tables to figure out how long you can stay underwater.
Dive tables are a fundamental tool for recreational divers. They give you the information you need to make a safe dive, and they can also save you money by helping you plan your dives before you go out.
How to read dive tables? Dive tables can be used to determine how long it will be safe for you to stay underwater when scuba diving. Dive tables are an important part of any diver’s toolkit because they allow divers who aren’t familiar with diving computers or other electronic devices to calculate their own dive times without purchasing expensive equipment.
Conclusion
If you’re interested in diving, we recommend that you learn the dive tables by heart. It might take some time to master them but once you do it will be easier for you to calculate your dive times.