The 6 Most Critical Freediving Mistakes: Safety, Technique and Depth

From the outside, freediving can look very simple: take a deep breath, dive in and go as far as you can hold your breath.

In reality, freediving is a sport that needs physiology, technique, mental preparation, good decision-making and safety discipline to work together.

Working with divers of all levels for many years, I often see the same thing: beginners and experienced athletes sometimes make the same basic mistakes.

And some of these mistakes do more than reduce performance; they can create serious safety risks.

Here are the 6 critical mistakes we see most often in freediving, and that we must always address.

1. Hyperventilating before the dive

One of the most dangerous misconceptions in freediving is the idea that taking fast, deep breaths before a dive fills the body with more oxygen.

In fact, hyperventilation does far less to raise the oxygen in your blood than it does to lower carbon dioxide (CO₂).

Why is this dangerous?

Rising carbon dioxide plays an important role in creating the urge to breathe. When we lower CO₂ by hyperventilating, the urge to breathe can be delayed.

Meanwhile, oxygen keeps being consumed.

As a result, the diver can reach dangerously low oxygen levels without feeling a strong need to breathe, and can lose consciousness due to hypoxia.

This is extremely dangerous underwater.

The right approach: adopt a natural, calm and unforced breathing pattern before the dive, and avoid hyperventilation and excessive breathing preparation.

Remember: a delayed urge to breathe does not mean your oxygen reserve has increased.

2. Training without a safety diver

Perhaps the most important safety rule in freediving is this:

Never dive alone.

But we are not only talking about having another person nearby.

For truly safe training, your dive partner must know freediving rescue procedures, actively follow you, and be in a position to intervene when needed.

Hypoxic blackout does not always come with obvious warning signs that can be spotted in advance.

A diver can lose consciousness while feeling fine.

Especially in depth dives, the risk continues as the diver approaches the surface and immediately after surfacing.

That is why the safety diver’s job is not just to watch the dive. It includes meeting the diver at the right depth, surface supervision and, when necessary, a rescue.

The right approach: do every dive with a properly trained safety diver who supervises actively, within a safety plan suited to the depth and conditions of the dive.

Having another diver in the same area is not, on its own, an adequate safety system.

3. Forcing equalization and ignoring warnings from your ears

As depth increases in freediving, ambient pressure rises. In particular, the pressure in the middle-ear space has to be balanced with the ambient pressure.

This is called equalization.

A common beginner mistake is to start equalizing late, or to apply more force when it fails.

Equalization should be done with the right technique and timing, not with force.

When equalization is late, a pressure difference can build up across the eardrum and middle-ear structures. Pain, a feeling of fullness and difficulty equalizing can follow.

Continuing the dive anyway increases the risk of barotrauma.

Experienced divers can also have equalization problems, especially when progressing to new depths, in a head-down position or when tired.

The right approach: start equalizing early, keep doing it regularly throughout the descent, and stop the descent when it becomes difficult.

If you cannot equalize, ascend in a controlled way and end the dive. Forcing equalization against pain is never right.

With recurring equalization problems, an assessment by an ear, nose and throat (ENT) specialist is important.

Reaching depth is not about forcing your ears; it is about developing the right equalization technique.

4. Constantly trying to go deeper without improving technique

Progress in freediving is often measured in metres.

20 metres, 30 metres, 40 metres…

But depth on its own does not show an athlete’s technical level or the quality of a dive.

A diver may be able to reach a certain depth, but do it by wasting energy, tensing muscles or using an inefficient finning technique.

In that case, trying to go deeper can simply make existing technical faults more obvious.

These points in particular are easy to overlook:

• Unnecessary muscle tension
• Inefficient fin kicks
• Poor body position and streamlining
• A faulty descent rhythm
• Inadequate equalization technique
• Incorrect weighting

A good dive should not be judged only by the depth reached.

The efficiency of movement, control of the dive, quality of equalization and a safe recovery at the surface matter at least as much as depth.

The right approach: improve your technique at your current depth before adding depth, reduce unnecessary movement, and have your dives reviewed by a qualified instructor.

Sometimes a controlled, technically successful 30-metre dive is a far more valuable training session than a forced dive to 40 metres.

5. Underestimating fatigue, stress and the need to recover

Freediving is not just a physical performance. Our mental state, sleep quality, stress level and how well we have recovered from previous sessions can all affect our dives.

A dive that felt easy one day feeling hard the next does not always mean our technical level has dropped.

Poor sleep, physical fatigue, illness, heavy stress or the effects of earlier dives can change our performance.

Not planning enough recovery, especially during consecutive depth sessions, is a significant mistake.

Another problem is athletes trying to fix a bad dive by immediately trying again.

Not every unsuccessful dive is a target that has to be repeated.

Sometimes the best decision is to reduce the intensity of the session, work shallower or end the day.

The right approach: adapt your training plan to how you feel physically and mentally that day, prioritise rest, and leave appropriate surface intervals between dives.

In particular, postpone diving when you are ill, have ear or sinus problems, are clearly fatigued or notice unusual symptoms.

Discipline in freediving is not only knowing when to dive, but also knowing when not to.

6. Going deep without understanding the limits of your equalization technique

One of the mistakes I see often is divers trying to increase their depth without properly understanding how their equalization technique works, in which conditions it is effective, and at which depths it may start to reach its limits.

Today there are countless online videos about the Frenzel, Valsalva and mouthfill techniques. But watching a video of a technique does not mean we can perform it correctly or use it safely underwater.

Each equalization technique has its own mechanics, advantages and limitations.

Valsalva, Frenzel and mouthfill: the differences

• Valsalva manoeuvre: uses pressure generated by the chest and abdomen. Although some beginners use it, it becomes harder head-down and at increasing depth. Done with excessive force, it is also risky for ear health.
• Frenzel technique: relies on coordinating the muscles of the tongue and throat to create pressure. Learned properly, it can give more controlled and efficient equalization than Valsalva. But as lung volume decreases with depth, moving usable air into the mouth and throat can become harder.
• Mouthfill technique: relies on storing air for equalization in the mouth in advance and using it in a controlled way on deeper dives. It requires precise coordination of the tongue, soft palate, glottis and cheek muscles.

There is one point I especially want to underline:

There are no fixed depth limits for equalization techniques that apply to everyone.

For example, it is not correct to say that Frenzel definitively stops working at 30 or 40 metres. That limit varies with the diver’s anatomy, lung volume, flexibility, technique, body position and the pressure conditions.

Likewise, learning mouthfill does not automatically mean you can safely dive deeper.

The risk of techniques learned from the internet

Videos and online resources can be useful for understanding the theory of equalization. But using the wrong muscle groups, failing to control the glottis or creating more pressure than needed can cause serious problems underwater.

As depth increases, even a small technical error can lead to losing equalization completely.

In that situation, forcing harder or continuing the dive increases the risk of middle-ear and inner-ear barotrauma.

The right approach: learn equalization techniques not just as movements but together with their anatomical and physiological mechanisms.

Assess with an experienced freediving instructor which technique suits your current level, why you struggle at a certain depth and when to move on to the next technique.

Start with controlled technique work on land, then shallow-water practice under proper supervision, and then progress gradually.

When you cannot equalize, stop the descent; never force through pain.

Remember: understanding why and where your current technique reaches its limit is as important as learning a new equalization technique to go deeper.

Conclusion: a good freediver learns from mistakes

Progress in freediving is not only about holding your breath longer or reaching greater depth.

Real progress means understanding our body, learning the right techniques, putting safety first and assessing our own limits realistically.

Avoiding hyperventilation, training with a proper safety diver, not forcing equalization, focusing on technical development, prioritising recovery and understanding the limits of the equalization techniques we use are the cornerstones of a sustainable freediving journey.

This is one of the things we care about most in our training at Life Aquatic: not just helping students reach a certain depth, but helping them become aware, safe divers who understand why and how they dive.

Because the most important achievement in freediving is not reaching the next metre, but returning safely from every dive.