Must see documentaries..

[Two Gun Bob]

One thing why do the rescue team not wear breathing apparatus ??

There were in fact technical divers in the vicinity, and probably one of these should no doubt have been on standby for a safety assist as opposed to priorities with filming. This was an attempted dive on the Blue Hole and not an attempt on the free dive depth competition where rescue divers worked to 40 meters presamably due to gas/mixture restraints. The official AIDA incident report is available online to view.

Quick read from Wiki on the demands of the Blue hole on the Sinai in Egypt

Blue Hole (Red Sea) - Wikipedia

en.wikipedia.org

Re Lipski's uncontrolled descent, this will have been down to pressures at depth were free fall is accelerated and boeyancy diminished. Not bothering to search it out on the youtube but apparently it's there

 

[Big Joe Corrigan]

Just watched the Cavendish documentary, some amazing in-race footage, and quite emotional in parts.

 

[mancity2012_eamo]

Incredible.
One thing why do the rescue team not wear breathing apparatus ??

Because SCUBA gives you air at water ambient pressure.
Therefore you have to decompress slowly on the ascent.

If the free diver gets into trouble they have to be brought to the surface as quickly as possible. Therefore the recovery divers also have to be able to get them to the surface without decompressing.

They immediately close the throat so no water goes down into the lungs and rush the diver in trouble to the surface.
The heart is still pumping so depleted oxygen is still getting to the brain.
Although the diver may be passed out they still have a few minutes before permanent damage is done.
So speed is essential.

 

[pride in battle]

There were in fact technical divers in the vicinity, and probably one of these should no doubt have been on standby for a safety assist as opposed to priorities with filming. This was an attempted dive on the Blue Hole and not an attempt on the free dive depth competition where rescue divers worked to 40 meters presamably due to gas/mixture restraints. The official AIDA incident report is available online to view.

Quick read from Wiki on the demands of the Blue hole on the Sinai in Egypt

Blue Hole (Red Sea) - Wikipedia

en.wikipedia.org

Re Lipski's uncontrolled descent, this will have been down to pressures at depth were free fall is accelerated and boeyancy diminished. Not bothering to search it out on the youtube but apparently it's there

But none of the rescue divers have oxygen which is bizarre ?

 

[pride in battle]

Because SCUBA gives you air at water ambient pressure.
Therefore you have to decompress slowly on the ascent.

If the free diver gets into trouble they have to be brought to the surface as quickly as possible. Therefore the recovery divers also have to be able to get them to the surface without decompressing.

They immediately close the throat so no water goes down into the lungs and rush the diver in trouble to the surface.
The heart is still pumping so depleted oxygen is still getting to the brain.
Although the diver may be passed out they still have a few minutes before permanent damage is done.
So speed is essential.

Ah I see, thank you

 

[Longballutd]

Just binge watched Unchained tour de France on Netflix.don’t really understand the team aspect of it always thought whoever came first in the stages won.Really interesting the way the riders are treated.Some of the crashes are mad,and the scenery is amazing

Yeah it’s a great watch

 

[mancity2012_eamo]

There were in fact technical divers in the vicinity, and probably one of these should no doubt have been on standby for a safety assist as opposed to priorities with filming. This was an attempted dive on the Blue Hole and not an attempt on the free dive depth competition where rescue divers worked to 40 meters presamably due to gas/mixture restraints. The official AIDA incident report is available online to view.

Quick read from Wiki on the demands of the Blue hole on the Sinai in Egypt

Blue Hole (Red Sea) - Wikipedia

en.wikipedia.org

Re Lipski's uncontrolled descent, this will have been down to pressures at depth were free fall is accelerated and boeyancy diminished. Not bothering to search it out on the youtube but apparently it's there

The 40 metres thing is a restriction on sports diving or recreational diving I think they call it.
Sports diving doesn’t condone decompression diving, beyond mandatory 3m6m stops.
Diving on air you have very little time at 40 metres without lengthening your decompression times once you get up to beyond ten metres.

Technical diving on something like trimix involves reducing the oxygen and introducing helium instead so you can go deeper, but the article you included explains the limitations for this site because of the number of bottles you would need to bring down beyond 55 metres and the length of the decompression stops that would be involved.

Basically every 10 metres of water is equivalent to one atmosphere at sea level. So the greatest increase in ambient pressure is in the first 10 metres. Pressure is doubled on the body.
There is 21% oxygen in normal air mix. This is measured as partial pressure of 0.21
The thing is oxygen becomes toxic to the body at a partial pressure of around 1.4
This means diving on air at around 60 metres is highly dangerous as you are at 7 atmospheres of pressure.

Tech diving is very specialised and extremely dangerous too. They reduce the oxygen to reduce the partial pressure but you can suffer from nitrogen narcosis which can render you….. well dopey.


So you can see that no matter what way you look at it, free diving is living on the edge for everyone involved. It really must be a drug. Adrenaline junkies.

 

[kippax123]

Just watched Profile on Netflix . True story of a journalist who attempts to expose a terrorist recruiter through social media. Really good film, well worth a watch.

 

[Two Gun Bob]

But none of the rescue divers have oxygen which is bizarre ?

We used to set closed circuit for pure oxygen, or mixture diving dependent on job typo. Pure oxygen is toxic below 8 meters that's why rescue divers couldn't use it. For deeper dives, variation of mixtures are used such as 60/40 or 40/60. For more depth, mixes with helium that replace much of the nitrogen. Nitrogen narcosis poisoning or raptures of the deep become a real issue at depth.

 

[mancity2012_eamo]

We used to set closed circuit for pure oxygen or mixture diving dependent on job typo. Pure oxygen is toxic below 8 meters that's why rescue divers couldn't use it. For deeper dives variation of mixtures are used such as 60/40 or 40/60. For more depth mixes with helium that replace much of the nitrogen. Nitrogen narcosis poisoning or raptures of the deep become a real issue at depth.

This.
Far less long winded than my contribution.