Freediving Cheat Sheet

The key takeaways for beginners – learning Frenzel equalising, the duck-dive entry underwater and staying safe through the buddy system.

Equipment

Item	Priority	Tip
Mask	High	Low-volume saves precious equalising air at every metre – the key difference from a scuba mask.
Fins	High	Long and flexible for more thrust per breath – full freediving fins only once your ankles are trained.
Wetsuit	Medium	3 mm for mild water, up to 7 mm open-cell for cold – a tight fit is what keeps you warm.
Weight belt	High	Fine-tune in 0.5–1 kg steps, buckle always within reach for an emergency release.

What makes freediving different

One breath instead of a tank: Seconds to minutes of dive time instead of 40–60 minutes – but almost no gear and near fish-like movement.
A different buddy principle: One dives, one watches from the surface – never descending together like in scuba diving.
Frenzel instead of Valsalva: The tongue technique works reliably to 25–30 metres and beyond, where Valsalva runs out of lung air.

The 3 golden technique rules

Factor 1: Frenzel early and often

Concept: Equalising is a rhythm, not a reaction to pain – Valsalva simply runs out of lung air at depth. Tip: Start already at the surface, then repeat every 1–2 metres. On pain, ascend a bit immediately instead of forcing it.

Factor 2: The duck-dive uses your legs as a lever

Concept: Your descent momentum comes from the weight of your straight legs, not from arm strength or early kicking. Tip: Fold your torso at the hips, pull your straight legs out of the water – only kick once your fins are fully submerged.

Factor 3: Recovery breathing protects the most dangerous phase

Concept: The first 30 seconds after surfacing are the most dangerous – oxygen levels can briefly keep falling. Tip: Inhale fully, hold briefly with a slightly closed glottis, then exhale against resistance – continue for at least 2 minutes.

Recognising blackout & samba

Warning sign	How to respond
Hyperventilating	Artificially lowers CO2 and delays the urge to breathe – the most common cause of blackouts.
Samba (LMC)	Uncontrolled shaking while fully conscious right after surfacing – take it seriously, not a minor issue.
Blow-tap-talk	Mask off, blow on the face, talk, tap – most people respond within 10–15 seconds.
After an incident	End the diving day immediately – regardless of how recovered you feel.

The freediving buddy system

One up, one down: Never descend together like in scuba diving – your buddy watches over you from the surface.
Watch the ascent closely: The last few metres before the surface are the most dangerous phase for a blackout.
Stay within arm's reach: Sight distance isn't enough – only arm's reach allows a reaction in seconds instead of half a minute.
Keep watching for 30 seconds: A blackout can also happen at the surface – only look away once recovery is clearly visible.

Pro tip: Your dive reflex slows your pulse by 10–25% untrained, by up to 50% trained – but never combine CO2 and O2 training on the same day, and never train without an alert buddy, even on land.