Ocean Siblings

Advanced Freediving Test

10 questions on advanced physiology, safety and technique. Recommended if you already have freediving experience.

Question 1 What is the main physiological cause of shallow water blackout during ascent in deep freediving?

Excessive accumulation of CO₂ in the blood during ascent A sudden drop in the partial pressure of O₂ as hydrostatic pressure decreases during ascent A glottic spasm caused by cold water

Question 2 During static apnea, in what approximate order do involuntary diaphragmatic contractions appear in relation to the breaking point?

They always appear after the breaking point They precede the breaking point and are a normal sign of rising CO₂, not necessarily lack of O₂ Diaphragmatic contractions and the breaking point are the same physiological event

Question 3 What does Boyle's law describe in the context of deep freediving?

At constant temperature, the volume of a gas is inversely proportional to pressure The partial pressure of a gas increases with water temperature Lung volume remains constant regardless of depth

Question 4 Blood shift in deep freediving allows:

The heart rate to increase to compensate for muscular effort Blood plasma to shift into the thoracic region, helping protect the lungs from compression at depth The concentration of CO₂ in the blood to decrease during descent

Question 5 At what theoretical depth would the lungs reach residual volume and pulmonary squeeze become possible, assuming a total lung capacity of 6 L and a residual volume of 1.5 L?

Approximately 10 metres Approximately 30 metres Approximately 50 metres

Question 6 According to AIDA/Molchanovs safety protocols, what is the correct buddy response to a possible loss of motor control (LMC) at the surface?

Wait 30 seconds before intervening to confirm that it is not a voluntary pause Provide immediate tactile stimulation to the face, use a firm verbal command and prepare for rescue procedures Immediately begin CPR

Question 7 What effect does hyperventilation before a breath-hold have on the CO₂ threshold and actual risk?

It significantly increases available O₂ and reduces the risk of hypoxia It lowers arterial CO₂ (hypocapnia), delaying the urge to breathe and allowing O₂ to fall to dangerous levels before the need to breathe is felt It stabilizes both O₂ and CO₂ and makes breath-holding safer

Question 8 In dynamic apnea (DYN), which factor has the greatest impact on O₂ consumption per unit of time?

Fin length Kick frequency and unnecessary muscular tension caused by inefficient technique Water temperature above 22°C

Question 9 According to diving reflex physiology, which combination of stimuli generally produces the strongest bradycardic response?

Breath-holding alone, without contact with water Breath-holding combined with facial immersion in cold water Breath-holding combined with intense leg exercise

Question 10 What is middle-ear squeeze and what directly causes it during freediving?

Neck muscle pain caused by descent posture Barotrauma caused by failure to equalize middle-ear pressure as hydrostatic pressure increases during descent An involuntary diaphragmatic contraction below 20 metres

Answers to review