Text: René Lipmann Photos: Daan Verhoeven

Sebastian Tjeerde is a freediver and a real competitive animal. His ambition? To keep improving his personal records for all disciplines. How? By training a lot in the gym, doing training sessions abroad and following training schedules in the swimming pool. To gain experience, he represented the Netherlands at the AIDA World Championship freediving depth.

You are a fanatic freediver. Are you purely active as a competitive athlete? Or can you also enjoy the underwater world in?  

I have been freediving for 6 years now. In the beginning I focused on training in the pool and open water to master the technique. The association I am a member of organizes a freedive competition every year, in 2019 I also participated in this competition. Since then I have not missed a pool competition. In addition, I have dived in various places to view underwater life, for example in Zeeland or abroad.

Have you always been competitive? What draws you to compete in freediving competitions? To measure yourself against others?

Before I started freediving, I was also active in underwater hockey for years. In the winter months I am part of a team and we participate in the Dutch competition. A freedive competition is mainly a competition with yourself. I always try to get further than I have been before. I use the tension I experience during competitions to get more focus and that makes it easier for me to find my limits. In addition, it is a nice snapshot in a controlled environment with safeties and judges.

Which part of the different freedive disciplines is your favorite?

My favorite discipline, both in the pool and in the deep, is swimming with the monofin. I swim with a monofin in a cadence of 2 strokes and then a moment of rest. This rhythm puts me in a certain trance, which makes me less focused on the fact that I am holding my breath.

A special part in my opinion is static, here the freediver lies on the surface with his or her face in the water and holds his or her breath for as long as possible. 

How do you deal with the moment when everything in your body is screaming? air now! Can you delay that? Do you have a technique for that? 

You need to ensure relaxation. This relaxation applies to both your body and your thoughts. If you are in a busy period, for example with work, this can affect your overall relaxation. The more tension, the higher the oxygen consumption and then you can of course lie under water for a shorter time. But even while lying down you need to ensure that you remain as relaxed as possible. Thoughts such as “oh my gosh i need to breathe” are absolutely not helpful. They just take you out of your focus. It is easier said than done, but the best thing is not to think about anything. I think you are always thinking about something, so it is important that you keep control over what you are thinking about. You can do this, for example, by imagining a song, visualizing something or feeling whether your whole body is relaxed. Static is currently my least favorite discipline, but is necessary to advance in other disciplines. I train statically, but the results vary greatly.

I've seen you training in the Vinkeveense Plassen, where it is up to 50 meters deep.

How deep do you go in this pool? After ten meters it gets pretty cold and dark. What is it like to train in the Netherlands? Aren't you already behind compared to athletes who train in, say, Dahab? 

The buoyed diving area in the Vinkeveense Plassen is an easily accessible area for freediving with excellent depths to practice different techniques. In addition, I dived a few times last summer at the 50 meter spot in preparation for the AIDA World Cup freediving depth. Training in the Netherlands has its challenges. The water can be quite cold, especially with the thermoclines, and it is dark at depth. Nevertheless, you have to ensure that relaxation. I am particularly bothered by the cold. It takes energy to stay warm and maintaining focus is difficult when the temperature suddenly drops 3 to 5 degrees. The advantage of training in the Netherlands is that you learn to deal with those conditions. You know what it is like to dive in cold water in the dark. If you then go to Egypt or Greece with this preparation, it is a world of difference. The water is clear, it is light around you down to the depth where I go and the water is pleasantly warm. Your body then needs less energy to stay warm and the light and visibility ensure more pleasant diving conditions. Being accustomed to the more challenging conditions in the Netherlands makes diving in warmer waters much easier.

Do you train abroad yourself? What are the circumstances like? Where do you like to go? 

In the Netherlands I can train my techniques well, but to actually reach depths it is necessary to go abroad where the sea is deeper.

Last year I started training in Dahab in Egypt. This location has good conditions for freediving all year round. The Blue Hole is an ideal place to train at depth. Later in the year I went to Kalamata in Greece several times. The sea there is mirror-smooth, deep, clear and fortunately without currents. And I just love Greek food.

Last year you participated for the Netherlands in the AIDA World Freediving Depth Championship. 

How do you actually qualify for such a World Cup? What did you learn from this participation?

For the last AIDA World Cup depth there were two athletes who were interested in participating. A country is allowed to send four athletes per gender. Because of this there was no need for qualifications and both athletes could participate in the AIDA World Cup.

During this World Championship I learned that I can trust that I have mastered my techniques well enough, even if I have to perform at a set time under competition pressure. And that it is even possible to go deeper than I have achieved before, which also creates extra tension. It was my idea to participate in a World Championship once, so that I could cross it off my bucket list. Because of the experience I have gained, together with getting to know all the other athletes and the nice atmosphere, I want to participate in a World Championship more often.

What does your week look like leading up to a big freedive competition? Do you follow a schedule? Do you do any specific training besides in the water? 

When a competition is coming up I don't do much differently than I normally would. I do stretch every day for flexibility. If it's a deep competition I do exercises to keep the technique for clearing smooth and efficient. I go to the gym regularly for muscle building and endurance, but I stop doing that the week before a competition. To give my body the time to recover and rest as well as possible.

Do you have a freediving 'hero'? Someone who inspires you? 

I think the word 'hero' is a bit of an exaggeration, but I think Alexey Molchanov fascinating indeed. He is a multiple world champion (AIDA and CMAS) and world record holder. He makes it look so easy when he dives to a depth that is almost my personal record. He is definitely someone who inspires me to keep training.

When it comes to freediving I often hear about feel uncomfortable, but what does that actually mean? How do you let go of this discomfort? How do you deal with fear? 

If you hold your breath longer, the breathing stimulus will cause your diaphragm to make pulling movements. This can make you feel less comfortable. By not focusing on this and accepting that there are physical reactions, you can learn to deal with it better.

What is your biggest challenge? What depth can or do you want to reach? Your ultimate PR?

During my last trainings I focused a lot on the technique of clearing ears and making it more efficient. Because you have more air left, you can keep clearing your ears longer, which allows you to dive deeper. With the current mastery of my clearing technique I have not yet reached my limit. The challenge remains to continue to optimize those techniques in order to reach deeper depths.

During a training year I always try to set intermediate goals to work towards. Usually this is a new personal record in a specific discipline or a good result at a competition. My ultimate goal is to get over 100 meters deep, that is a magic number for me.

I sometimes see images of Finnish freedivers under the ice of a frozen lake. There are even world records in that area… Have you ever dived under the ice of a lake? Would you dare, or would you pass? 

I have never done diving under ice, but it seems fantastic to do once. Dealing with the cold and the limited places in the ice where you can come up create extra tensions that have to be kept under control. That is quite challenging!

On February 1 and 2 you are a guest speaker at Duikvaker. What is your freedive presentation specifically about?

I will talk about the competitive side of the sport of freediving. I will tell you more about how competitions are conducted. I will also discuss my preparations for the AIDA World Cup depth and the course of the World Cup itself.

Sebastian Tjeerde, guest speaker Duikvaker 1 and 2 February 2025

Stage 2, 2:00 PM, The competitive side of freediving.