Types of diving · Self-contained diving · Apnea or Breath-hold Diving

When employing this technique the diver holds his breath without using any breathing apparatus and surfaces for new air. Breath-hold diving is divided into six main categories (not including the different varieties of each) which are very different from each other and which have different techniques and physical requirements.

Static apnea

Dynamic apnea

Free apnea

Constant weight apnea

Variable weight apnea

No limits

Static apnea
Static apnea consists in measuring the time the diver can remain underwater having inhaled air normally.

Dynamic apnea
This category measures the maximum horizontal distance a diver can swim on one breath of air. A sub category involves swimming with or without fins. This form of diving is not widely known and is not as important as others, thus not having as many enthusiasts as other forms.

Free apnea
This involves descending without fins using a fixed line to descend and surface. This form is not well known either.

Constant weight apnea
The free diver must reach the greatest depth possible using only fins and a fixed weight. The diver must come back up with the same weight used at the beginning of the dive. Due to this divers tend to use very little weight which makes the descent more difficult, especially for the first few meters.

In this category, the depth and the various consequences must be taken into account as the level of difficulty rises. For the first 20 meters an enormous amount of air is used in order to descend. Rising to the surface again is also challenging, as is finding the acceptable level of floatability.

For this and other reasons, constant weight apnea is considered the most difficult and competitive form of diving. The diver descends guided by a fixed line to which a small metallic tag is attached indicating depth.


Variable weight apnea
In this form of diving the diver is allowed to descend with a weight different to that used to surface. It is possible to leave a total of thirty kilos at the bottom in order to surface more rapidly and easily, but even so, using only fins. Adjustment to the surrounds and depth is especially important and poses the main challenge.

No limits
This form of diving is, without a doubt, the most sensational, dangerous and controversial forms of breath-hold diving. The name itself indicates the rules to be followed: no limits, anything goes when trying to reach the maximum depth using one normal breath only.

The freediver can descend with the weight he chooses and surface without it. Furthermore, inflatable lifting bags can be used to assist the diver in the assent at a greater speed. The weight is usually in the form of a heavy metallic bar that the divers can easily hold on to and which descends fixed to a line, reaching great depths. By releasing the break, the descent begins and once at the bottom, large lifting bags are inflated which surface rapidly, releasing air with the divers holding on to them.

Due to the great depths involved, this form of diving implies considerable danger and has known several victims. Besides, the various organizations that organize and promote breath-hold activities have not officially recognized no limits apnea, given that they’re not willing to deal with the consequent dangers, and have thus declared it an experimental activity.