How to choose a mask for Freediving

Probably the 1st thing your personal freediving equipment starts with is a mask and a snorkel.

freediving maskThis step is easy to explain: rental masks might not fit you well and can constantly leak. Besides, it’s always more pleasant to be the only one who wears the mask which touches your face. Also, you don’t depend on rental shops operation hours and with your own mask, you can go snorkeling or freediving wherever and whenever you want. And the last reason – it’s super easy to travel with a little mask in a bag. Way easier, than with a pair of freediving fins.

So how to pick up the decent mask? If you are already a certified Freediver, probably you know the answer. If not, let me explain

Remember one thing – the best mask for you is the mask, which fits you independently on cost and brand.

Let me give you a couple of advice on how to pick up the perfect mask.

It is always better to try the mask first. Ideally in the water, but at least in a shop.

And there are two main things you ’d better pay attention to mask shouldn’t hurt you and you should be able to equalize in it.

If you put the mask on your face and press on the top of the nose bridge and if you feelDCIM101GOPROG0091796.JPG little pain, this mask is not for you. As little pain can become a terrible headache after 1-hour freediving or snorkeling session.

Another important thing – equalization. Be sure that you can pinch your nose to equalize. Some masks have extremely huge nose pocket, like Omer Zero, and it’s a real challenge to find the nose in such a mask.

Let’s talk about the features, which mask should have to be suitable for freediving.

So, in freediving unlike to scuba diving to equalize the mask we are using our air from the lungs, which is limited and which we actually need to dive deeper. That is why for freediving mask it is extremely important to be as low in volume as possible. And single lens mask has always more volume then double lens one. In this concern, you need to look for a double lens mask. Soft silicone skirt is important as it seals better around the face. And except that it is much easier to pinch the nose for equalization. In this concern, PVC skirt masks are not a smart choice at all.

Let’s take a look at one example of the mask.

mask for freedivingYou might have seen many freedivers diving in Sphera mask by Aqualung. It’s a gorgeous not expensive and unique mask due to its bent lenses, which allows the mask to follow the shape of the face. This provides super low volume and high side vision. But to make the lenses curve manufacturer had to use plastic instead of glass. And plastic is much less resistant to the scratches. That is not a problem at all if you care your equipment well. In case, you have a habit to drop your mask anywhere but not in the box, probably you have to check for another option.

And the last thing which I would like to cover is the difference between brand and noname masks. Brands usually provide good warranty conditions and in case your mask is broken due to manufacturing failure, you can apply for warranty repair or replacement. But be sure you have saved the receipt to confirm your purchase. The best way is to take photos of all your receipts and keep the digital copies in case you lose a paper bill.

I hope all these tips will be useful for you when you come to the shop for your 1st Freediving mask.

And if you have any questions, please don’t hesitate to ask in comments below.

 

By Svitlana Gaidai

 

 

 

Everything that you need to know about MDR (Mammalian Dive Reflex) in Freediving

First of all the term, Mammalian Dive Reflex is a little bit misleading term since not only mammals have it. So, let’s call it Dive Reflex or Dive Response or just DR 😉

Doesn’t matter, you are complete beginners or you already Freediving Instructor, Dive Reflex is your best friend!

A bit of history. Many years ago one French doctor made a statement that man could not dive deeper than 50 meters because the thoracic cavity is going to be crushed (some sources say 30-40 meters). Why? Because every 10 meters pressure increasing with 1 atm and when you are 50 meters surrounding pressure already 6 atm. And it is huge. But back to those time, no one was even trying to do it (ok, there a couple of exceptions). But in 1961 Enzo Maiorca dived to this depth and survive! Why? Because of the blood shift! And blood shift is a part of DR!

DCIM102GOPROGOPR1302.JPGDR is activated when our face is cooled (by cold water for example) or when we hold our breath. When we do both – even better!

This reflex helps us to hold our breath longer and dive deeper! How? By:

  1. Apnea
  2. Bradycardia
  3. Peripheral vasoconstriction and blood shift
  4. Spleen contraction

1. DR is responsible for spontaneous activation of Apnea. If we place infant underwater (don’t ask me why) their windpipe would spontaneously close (by vocal cords) and this prevents water from entering the lungs. This reflex quite strong upon 6 months and then start to disappear. My assumption – around this age baby start learning how to crawl and probably decide that Dive Reflex is not that important for them! Does it happen because of our genetic memories of our aquatic past or because nine months before birth our natural environment is liquid? Who knows 😉

2. DR causing bradycardia – slowing your heart rate (HR). Quite common is 10-30 % DCIM102GOPROGOPR0029.JPGreduction of HR for Freedivers (up to 50% or more in highly trained athletes). There are stories with even more impressive results, but let’s skip them now. Sounds impressive? How about this – laboratory rats have 80% decreases in HR while submerged underwater!!

Bradycardia is usually followed by tachycardia (increase in HR) after breath hold is over.

Why bradycardia is important for Freediver? Well, it is a protective mechanism of our body, it decreases O2 consumption, which means we can hold our breath hold longer without risk of losing the conscious! It also compensates the result of peripheral vasoconstriction effect (which cause increased blood pressure)

3. Next benefit of DR is a peripheral vasoconstriction and blood shift

Back to 1974 study showed that during dives to 40-60 meters, the amount of blood in the thorax (chest cavity) increased more than twice! And this reflex was called (pretty obviously) blood shift.

DCIM102GOPROG0053175.JPGPeripheral vasoconstriction (PV) is a narrowing of the blood vessels to reduce blood flow to non-vital organs (such as skin or inactive muscles, for example) ensuring that oxygen-sensitive organs like the brain or heart receive enough O2 for normal function. In another word PV is a redistribution of blood to vital organs from peripheral organs. PV also induces anaerobic metabolism, with an increase in lactic acid as a by-product. Interesting that the release of lactic acid into the bloodstream doesn’t occur (or at least significantly reduced) until Freediver resurface (at least this is what experiments on laboratory rats show).

For all of the above, you can say that blood shift (BS) happens (blood moves from non-vital organs to vital organs) when PV happens, but quite common Freedivers are using the term BS when describing the movement of the blood to the chest cavity to protect it from increasing pressure while diving deep.

Due to PV certain amount of blood pushed to the lungs, the capillaries in the lungs receive a greater blood flow and increase in size, compensating for space lost in the lungs due to increasing of ambient pressure. The lungs become filled up with the blood, which is reabsorbed when Freediver ascending.

IMPORTANT! Blood shift not pushing the blood into alveoli! It pushes it into capillaries around alveoli!

Why PV is very important for Freedivers? Well, it helps to move O2 from organs which can survive longer without it, to organs which are in constant demand of O2. So, it helps us to hold our breath longer and dive deeper (by moving blood to the chest cavity).

4. And the last but not least benefit of DR is the spleen contraction. Spleen in the human body has two main functions – mechanical filtration of red blood cells (RBC) and as a part of the immune system. We are interested in the first function. About 240 ml of RBC’s can be held in the spleen and released when needed (due to hypoxia for example). When the contraction of the spleen happens oxygen-rich RBC’s gradually start their journey to circulatory system increasing O2 carry capacity of our blood (and helping us to hold our breath longer).

Interesting that spleen not recovering fast, even after an hour it is only partially recovered (however there are studies which show that spleen can be fully recovered in size in less than 20 minutes).

5. This is not a benefit, but still part of DR. Immersion diuresis. Yes, this is an explanation DCIM102GOPROG0022614.JPGwhy while Freediving you want to pee much often! As you know part of DR is PV and it causes increased blood flow to the torso area and increased blood pressure as a result. Our body detects it and releases a specific hormone responsible for liquid regulations, which increase urine production. Don’t be embarrassed because of it! But make sure that this reflex doesn’t make you dyhadrated (drink enough before and after Freediving session).

6. Another side effect of DR is faster muscles fatigue. And again you can blame PV. When PV happens and blood moves away from your muscles, they start to work in an anaerobic way and produce more lactic. And even after you finish apnea, the effect does not disappear quickly (depends how long and intense your apnea was). Do you need proof? Try to do DYN bi fins 100 meters and 100 meters surface swim (with the same fins) and compare how do you feel.

 

If you have any question about Freediving, let me know in comments below!

 

 

 

 

How to hold your breath

The basic skill which you learn on your first Freediving course is, of course, how to hold your breath! This Freediving discipline requires a minimum of Freediving equipment!!

A lot of my students, when I ask them, how long they can do it, answering – 30-40 seconds. And then in 10 minutes, they can hold for 1.5-2 minutes! Magic? Not really 😉 Simply understanding how to do it correctly, what happens in the organism during static breath hold – helps that much!

Watch how our student does it for the first time! Interesting to try? Come to Koh Tao (Thailand) and we going to be more than happy do Freediving course with you!

5 Rules for snorkelers

“Rules for snorkelers? I thought there are no rules!”

AdventuresOk, snorkeling is a natural activity for us humans (especially after we invented a mask) and everyone can do it without any education.

But as usual, if you want to do something safer – you should learn how.

And let me help you with that by sharing five safety rules for snorkelers!

Below is a short version, full version, as usual on my YouTube channel – Crystal Freediving 😉

Freediving vlog

Ok, it was a long time ago when I decide that I want to do Freediving blog. But writing in English is difficult. And after finish my first blog I was correcting it again and again until I just deleted it 🙂 Apparently with video it much easy since you posted – IT IS DONE!

That’s why the transition from blog to vlog was logical. And here we go, I am a vlogger on a YouTube! 😉

It is not the first episode, but since now I am going to post here a short version of it here. Hope you, my reader, will enjoy it!

If you are interested and want to see full version, find my channel on YouTube – Crystal Freediving