AIDA International is the worldwide federation for breath hold diving, a non profit organisation that was founded in 1992 to further the development of freediving. Over the years, AIDA International has defined disciplines in freediving and recognise and authenticate world records achieved in these disciplines.

The cessation of respiratory airflow. In freediving this is a voluntary breath-hold during a freedive or with the face below the surface of the water.

The physical damage of body tissues which results from a difference in pressure between internal body cavities and the external environment.

Fins specifically designed for freediving with long blades and soft pockets.

Blood flow to your extremities is redistributed to your head and chest during a freedive.

The bodily changes that happen during a freedive or freedive session, which allow your body to function more efficiently under new conditions. They generally disappear when you resume breathing.

Diving computer tracks the time, temperature, depth, speed etc… of the dives. Depending on the brand there are many functions like different alarms which notify the diver about certain parameters of the dive.

A freedive to depth, with the same weight for descent and ascent and using bi-fins or a monofin. Any technique.

A freedive to depth, with the same weight for descent and ascent using bi-fins. No dolphin kick.

A freedive to depth, with the same weight for descent and ascent. No fins.

A late warning sign that can precede a blackout. Involuntary contractions generally develop in the neck, shoulders, arms, and occasionally in the leg muscles. A loss of motor control can happen following a freedive if your oxygen levels are too low. Also known as a hypoxic fit, you are often unaware that it is happening. A loss of motor control is sometimes known as a 'samba' due to the jerky movements of the head, body and limbs.

A horizontal swim underwater, no fins.

A horizontal swim underwater, with bi-fins or a monofin.

The equalization of pressure between your body cavities and the surrounding environment as you freedive to depth. There are three main air spaces to equalize: your ears, more specifically your middle ear, your sinuses and your mask. There are a number of techniques which can be used to equalize the pressure in your air spaces, including Frenzel and Valsalva maneuvers.

A blackout is a loss of consciousness due to insufficient levels of oxygen in the body. A loss of motor control may result in a blackout.

Special type of google with an optic lens. Divers fill the google up with water due to the pressure in the depth, the lens corrects the water distortion so the diver has a clear vision underwater.

Functional Residual Volume. Refers to the volume of air in the lungs after passive expiration.

A freedive to depth by pulling down and then back up a dive line, with same weight for descent and ascent. No fins.

Pushing with your tongue or cheek muscles against your pinched nostrils to create air pressure. Also known as the Frenzel maneuver. Frenzel-manőverként is ismert.

Hypercapnia is caused by an elevated (more than normal) level of carbon dioxide in your blood.

An insufficient supply of oxygen to the body tissues.

A An involuntary spasm in your respiratory muscles caused by an elevated level of carbon dioxide in your body and the rising urge to breathe.

A safety lanyard prevents you from getting lost in the open water. One end of the lanyard is attached to a dive line and the other to you.

Used by freedivers when resting at the surface. Freedivers use simple snorkels without valves.