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  9. Understanding Dive Tables – Beginners Guide

Understanding Dive Tables – Beginners Guide

Understanding Dive Tables – Beginners Guide

Dive tables are meticulously crafted charts which provide safety information to divers venturing into the ocean. It contain information like how long one is allowed to remain at a specific depth, how deep they could go with the amount of air they are inhaling, how often they should resurface and much more.

Understanding dive tables for new divers

Dive tables help divers determine how long they can stay underwater at a given depth, how long their surface time frames should be, as well as how to calculate the amount of residual nitrogen in their blood after a dive. Before you’re a qualified scuba diver, you’ll need to be really familiar with dive tables. Understanding it is not a necessary skill these days. But thanks to the introduction of dive computers. It is useful to always have a basic comprehension that these chart provide. These are essentially charts with alphanumeric characters referring to sea level and timeframes. These charts are frequently printed on booklets and water resistant plastic cards. Divers carry them during dive reference.

What it does and how to read it?

All this preparation is required where there are very real risks involved with diving. Precautionary measures are required to avoid decompression sickness (DCS), as well as the injuries that comes along with it. Even with being a robust machine, the person’s body had already adapted to easily manage on its own. To survive in normal temperatures and pressures on land. When we dive, we are subjected to ambient pressure from the water surrounding us, applying pressure into our bodies. When we go deeper, the pressure rises and reaches to our inner tissues, arteries, and organs. Under normal temperatures and pressures, the gasses that divers inhale from their tanks are calibrated. As the diver descends, these gasses dissolve in their bloodstream to equalize the pressure inside their body with the weight of the water on their skin.

To express the level of residual nitrogen in your body, the NAUI Dive Tables are using a Letter Group classification. The letters are arranged in alphabetical order, beginning with A and ending with L. The letter A represents a tiny amount of nitrogen. So as the letters progress towards L, the amount of nitrogen rises. Once you dive, a Letter Group from the table indicates how much nitrogen you absorbed during the dive. As you off gas nitrogen, you are allotted to “lower” Letter Groups as you spend quality time on the surface between dives.

Importance of Dive Tables

Dive tables have been previously developed by the United States Navy as a protection guideline for their divers. With technological developments, you can already obtain the same data from a small dive computer which can be worn on the wrist. They’re usually outfitted with sensor systems and timers to keep an eye on the diver on a real – time basis. If you’re just a beginner or a seasoned decompression diver, knowing your limits and instructions underwater is critical.

Are dive tables still present?

Dive tables are both beloved and despised by recreational divers. Some divers regard them as an anachronism, a remnant from a bygone era, in such an age of cheaper wrist-mounted diving computers. Others regard dive tables as a treasured memento of their diving growth. A sentimental link to the past and the repository of conceptual understanding that lurk behind the whirring algorithms of their outdoor recreation computers.

Many recreational organizations have gone so far as to make dive table use purely optional during scuba diving training.


Before, divers cannot measure or determine how long they can stay underwater. It is a must that every divers should bring their dive tables when going on a dive. Nowadays, there are many technological advancements. Dive tables might not be reliable, but having one might still help a diver. Keep your dive table in a storage away from any damage.


Examine your dive table if you’ve never used it for a while. Make yourself acquainted with it. Even when you’re not using it frequently, understanding the theory behind such a development is essential. One day, it might even prevent you from canceling or missing a dive.


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