Freediving – how many minutes does an extreme depth dive take?March 24, 2009
I was asked how long it took Herbert Nitsch to descend to 214m (extreme by anyone’s standard) and return to the surface, and I couldn’t find that information anywhere. Static time underwater is timed, but with depth dives it’s the depth that’s more important – not the time it takes although that is of course interesting … or so it seems.
I did find that on 17th March, whilst training for the competition at Dean’s Blue Hole, Herbert made a training dive to 92 meters. To reach the depth it took him 1min 38sec, and the total divetime was 3min 51sec.
If you are wondering how freedivers manage to achieve these record-breaking dives, Kerian Hibbs, who is also out there training at Dean’s Blue Hole, kindly took the time to explain it to me yesterday – so, from the horse’s mouth, here goes:
“The dives to depth in time do not relate to pool at all, and this description will concentrate on inhale dives only.
When you inhale ready to dive on the surface, you then pack to maximum capacity. Of course this means that your chest cavity is bloated and ribs stretched. As you go deep the pressure makes the air in the lungs compress, so the pressure you feel on the surface (being stretched) reduces pretty quickly, say 3m and its comfortable again, but of course in doing so the pressure inside your lungs actually increases as the depth increases. So really, capacity does not change at all, its just volume changes.
Obviously as the depth increases, so does the time of the dive. The dive profile that most people get on the descent is around 1m/s, therefore a 90m dive (in theory) should reach the bottom at around 1 min 30 seconds. This is highly dependent on streamline, efficiency, kick strength, kick amplitude / frequency and buoyancy (at the surface – as this needs to be overcome before freefall can occur).
The ascent is different for all athletes and of course disciplines. You would expect that “constant weight no fins” will be slower ascent rate than with a wacking great monofin strapped to your feet” – however it depends on each individuals particular style and strengths.
To illustrate this, Kerian’s dive to 71m was 2 min’s 20 seconds. The descent was 1 min 18 seconds (slightly slow) but his ascent was pretty quick as he is efficient through the water due to his ‘Dynamic Style’ being pretty good.
Kerian tells me that there is a trend emerging where it looks like a lot of the divers are trying to come off the bottom faster than has been typical in the past. He attributes this to trying to avoid (CO2) Narcosis which bites pretty bad as the dives get longer.
This is an amazing video of Willaim Trubridge (williamtrubridge ) setting a new world record in 2007 – it gives an idea of the simplicity, achievement and extroadinary elegance of this silent and extreme sport. As Kerian says: “one dips slowly beneath the surface, opens ones eyes and finds oneself in another dimension…the pleasure is immediate”.