Orientation during deco/safety stop

[lamont]

I don't know why DIR/GUE types spend so much effort trying to theorize why horizontal deco is better from a deco perspective, when its clear that there's zero actual evidence to support any of the theories...

The reason which settles the debate for me is that if you either lose buoyancy upwards or downwards that being horizontal gives you a much better ability to change trim and kick. If you are vertical and lose buoyancy upwards you need to flip through more than 90 degrees to be able to kick down. There doesn't need to be a complicated physiological reason for horizontal deco.

Plus it looks cooler.

 

[ianr33]

If you are on O2 with your chest at 19 feet might your toes tox??

 

[Dr Deco]

Hello readers:

Off Gassing

If truth were known, the biggest assist in unloading nitrogen from the tissues is an increase in the blood supply to that tissue. This is accomplished by muscle movement that will cause an increase in heart rate, and dilation of the arterioles, and activation of the “muscle pump.”

All of this will be accomplished by movement during the deco stop. Therefore, the best deco position is one where the diver can perform gentle bicycling motions while in the water. In whatever orientation you wish to accomplish this is up to the diver.

Dr Deco :doctor:

The next class in Decompression Physiology for 2006 is September 16 – 17. :1book: http://wrigley.usc.edu/hyperbaric/advdeco.htm

 

[gcbryan]

I don't know why DIR/GUE types spend so much effort trying to theorize why horizontal deco is better from a deco perspective, when its clear that there's zero actual evidence to support any of the theories...

The reason which settles the debate for me is that if you either lose buoyancy upwards or downwards that being horizontal gives you a much better ability to change trim and kick. If you are vertical and lose buoyancy upwards you need to flip through more than 90 degrees to be able to kick down. There doesn't need to be a complicated physiological reason for horizontal deco.

Plus it looks cooler.

You've hit on an interesting point. Why do DIR types (yes, I understand that you're one) spend so much effort trying to theorize why every aspect of DIR philosophy/technique is the only reasonable way to do things? The worthwhile aspects sell themselves.

People may seek out a Mercedes dealership while they run from the Jehovah's Witness at their front door

 

[Kevrumbo]

I don't know why DIR/GUE types spend so much effort trying to theorize why horizontal deco is better from a deco perspective, when its clear that there's zero actual evidence to support any of the theories.....

Quantitatively no evidence (yet); qualitatively it just makes good intuitive sense.

The reason which settles the debate for me is that if you either lose buoyancy upwards or downwards that being horizontal gives you a much better ability to change trim and kick. If you are vertical and lose buoyancy upwards you need to flip through more than 90 degrees to be able to kick down. There doesn't need to be a complicated physiological reason for horizontal deco.
Plus it looks cooler.

In a drysuit with a dramatic loss of buoyancy (i.g. runaway inflator), last resort is to be head-up vertical, dumping gas from your suit and/or wing, and disconnecting hose(s). . .

 

[LavaSurfer]

I saw a diver do something really smart once...she brought a lanyard with her and tied it to the anchorline. That way, she could hold on to her lanyard a little bit off of the line and not get in the other divers' way. Cool idea.

Avoids Fire coral burns too!

 

[Charlie99]

I saw a diver do something really smart once...she brought a lanyard with her and tied it to the anchorline. That way, she could hold on to her lanyard a little bit off of the line and not get in the other divers' way.

A "jon line" is the term usually used for those lines. While horizontal vs. vertical doesn't seem to have much effect on deco, getting jerked around by a mooring line has been implicated many times in DCS incidents.

A jon line isolates one from most of the anchor/mooring line up/down movement. You can also clip on and reduce the likelyhood that you get DCS in the arm from getting jerked around. Real world problems that aren't as sexy as "horizontal vs. vertical, but in reality are more important.

Of course, drifting deco avoids the problem, but introduces the alternate risk of separation from the boat.

 

[netmage]

You've hit on an interesting point. Why do DIR types (yes, I understand that you're one) spend so much effort trying to theorize why every aspect of DIR philosophy/technique is the only reasonable way to do things? The worthwhile aspects sell themselves.
/QUOTE]

Not all of them pound the pulpit..., you'll find 1%'ers in every crowd and newbie internet divers who latch onto the philosophy with some sort of cult mentality... Its not really that at all, and its a shame some folks have twisted it to that extreme. No offense to Kevrumbo - I started to cringe when he said "in my DIR-F"...

The concepts when evaluated rationally tend to make alot of sense - or at least they did to me. Not everything in DIR is strict 'adherence' as you mention... There are a few items which are non-starters for debate - mostly revolving around dealing w/ an OOA situation. Some of the other items come into play as you progress more and more into tech diving and scootering.

The horizontal attitude minimizes your cross section in the water, plays in naturally with the frog kick, allows you to demonstrate you jedi like ability ascending while the rest of the folks are crammed up on the line at 20' for their safety stop and show off back-kicking around them...

 

[Kevrumbo]

PADI never explained it other than to "hold your safety stop, depth measured at chest level". Look, the DIR folks never claimed to have all the Answers on Safe Diving Theory & Practice --but IMO, they seem to have at least a better understanding of the basic relevant Questions. . .

 

[Cacia]

one little point...
does anyone remember the L ventricle down position?

has that been totally debunked as far as where bubbles lodge, float?