Charts and Tables
What exactly are the dive charts and tables?
Itīs simple, they are scientific parameters that will tell us for how long we can dive at a certain depth with a very small risk of getting sick with something commonly known as "the bends", wich is excess of nitrogen in our body.
When you go underwater, the sorrounding pressure or force exerted on your body by the environment -water- will increase and this will cause a greater nitrogen intake during the dive. Although nitrogen is an inhert gas, it can damage your body if it gets out of solution due to high levels. Donīt forget that nitrogen is present on air in a 79%.
Warning: The charts cannot predict, at all, how long does our air supply -that includes the 21% of oxygen of course- will last at a certain depth. Instead, their purpose is to show how much nitrogen are we intaking at a certain depth. By the way, you use the air gage in your console to monitor the air level in your tank.
There are several dive tables and all are based on the same principle, what changes though is the formula they use to calculate the nitrogen intake during the dive. What this means is that the safe limits for a particular dive or series of dives will change according to the chart that you consult. All the different versions have the same restriction, they cannot guarantee that you wonīt get "the bends" even if you respect their limits.