tWO DIVERS PULLED DOWN 64M

[cdiver2]

tAKEN FROM YORKSHIRE DIVERS BOARD

Two divers pulled 64m down in Cook Strait
29 August 2005

By COLIN PATTERSON

A diver is missing and another seriously ill with the bends after being sucked under turbulent water in Cook Strait.

They were dragged 64 metres below the surface near the Brothers Islands, north of Tory Channel, yesterday afternoon.

One diver made it to the surface and was taken on board the dive boat, feeling unwell. He lost sight of his mate coming up. The skipper put out a distress call. The Wellington-based Westpac rescue helicopter was on the way within four minutes, operations manager Dave Greenberg said.

A Wellington Free Ambulance paramedic was winched on to the launch, in 40km/h winds and two-metre swells.

The sick diver was flown to Wellington Hospital. He was then taken to Christchurch Hospital's decompression unit by the Life Flight fixed-wing air ambulance.

The rescue helicopter, with two police dive squad members, joined boats in looking for the second diver. He was not found before dark. The search will go on today.

 

[TheDavil]

I gotta tell you - this is the part of diving that (probably irrationally) scares me the most. The thought of getting caught in a downswelling like this just gives me the willies.

What causes this phenomena? How wide is/can the 'downdraft' be?

What is the proper thing to do in this sort of situation? Is it the same as a riptide, where you try to swim perpendicular to the flow until you got out of it?

Thanks,
David

 

[H2Andy]

A Wellington Free Ambulance paramedic was winched on to the
launch, in 40km/h winds and two-metre swells.

why were they diving in those conditions?

 

[Doc]

I gotta tell you - this is the part of diving that (probably irrationally) scares me the most. What causes this phenomena? How wide is/can the 'downdraft' be? What is the proper thing to do in this sort of situation? Is it the same as a riptide, where you try to swim perpendicular to the flow until you got out of it?

First, you have to recognize it, most do not.

Fear of this is not irrational. Go with the best advice of local dive guides.

Usually two currents converging from shallow areas and being presented with a bottomless cliff to spill over and down.

Look ahead at the corals and critters. Good indicator.

After recognizing it, you must react decisively.

Yes, kick to the sides and up.

Blow your BC

Ascend slowly and in control once you get out of it. Take panic out of the equation.

They can be as wide as an escalator or hundreds of feet accross.

In the Caribbean, find this in Tobago.

The Galapagos.

 

[cdiver2]

why were they diving in those conditions?

May be they were diving without local knowledge (DM) or a local

 

[Otter]

May be they were diving without local knowledge (DM) or a local

Or maybe conditions changed during the dive?

 

[pilot fish]

First, you have to recognize it, most do not.

Fear of this is not irrational. Go with the best advice of local dive guides.

Usually two currents converging from shallow areas and being presented with a bottomless cliff to spill over and down.

Look ahead at the corals and critters. Good indicator.

After recognizing it, you must react decisively.

Yes, kick to the sides and up.

Blow your BC

Ascend slowly and in control once you get out of it. Take panic out of the equation.

They can be as wide as an escalator or hundreds of feet accross.

In the Caribbean, find this in Tobago.

The Galapagos.

By "blow your BC" do you mean inflate it, max, a little

 

[Doc Intrepid]

blowing a liftbag may (or may not, depending on the downwelling) also provide some upward lift, or delay your descent, as would (naturally) trying to make it to the wall and hanging onto it.

So much of how you would respond is situationally-dependent that its tough to offer one, glib, solve-all response. (No, I've never been caught in a downwelling...)

One issue these divers faced is, assuming they only had single cylinders, simply ascending from that depth given hyperventilation, anxiety, hypoxia, etc. presents major challenges.

Your options are limited, however, if you've adequate gas and some sort of reel and liftbag you at least have some options - otherwise you're SOL...

 

[Web Monkey]

Is it actually possible that a 90Lb lift bag wouldn't be enough to keep you from sinking?

That's creepy!

Terry

blowing a liftbag may (or may not, depending on the downwelling) also provide some upward lift, or delay your descent, as would (naturally) trying to make it to the wall and hanging onto it.

So much of how you would respond is situationally-dependent that its tough to offer one, glib, solve-all response. (No, I've never been caught in a downwelling...)

One issue these divers faced is, assuming they only had single cylinders, simply ascending from that depth given hyperventilation, anxiety, hypoxia, etc. presents major challenges.

Your options are limited, however, if you've adequate gas and some sort of reel and liftbag you at least have some options - otherwise you're SOL...

 

[Seadeuce]

See the following thread:

http://www.scubaboard.com/showthread.php?t=48956&highlight=downcurrent

Seadeuce