DIR Details

[matt t.]

Steve,
Interesting explanation. I've never heard of that, but would be interested to see it "in action". I like the idea, but I don't think most people would wait around to see if it would work (or even have the presence of mind to try it.) It is something for me to store away though. Thanks!


Matt

[FreediveWI]

I've done it many times with people out on Lake Michiga They usually have their IP set to high on their regs and they start to freeflow when wreck diving. I just hand off my reg, on a 7' hose, to them and shut their tank off. I wait about a minute and turn it back on. They can then continue the dive. It might help that I was wearing doubles so I could donate and not have to worry about gas, but I have done it with my single tank set up as well on dives above 100' with plenty of gas to spare.

Jon

[DRE]

First of all I'd like to say that I'm impressed with the way people discuss DIR on this site: it's much more open and much less BS thanon the MNscuba site. Congrats on that!

I've been reading through the archives here, so I'm sorry if I may point out something that's already been covered before, or if I'm resurfacing an old thread. But I do have a bit of an issue with the comment below. I can agree with you Greg, that computers may be useful for non-deco diving, but since it is within the DIR context, why not just use a BT for all rec and tec diving? If you're using the correct gasses (critical within DIR) and you're doing the correct ascents (very critical within DIR) there's no need to track residual nitrogen and/or O2 limits with a computer - a simple BT will suffice, and I don't think most people would have too many prolems adding up to 120 (if they can't, they deserve to be duped into buying a $1000 computer ;D)
I believe DIR is all about simplicity, and using a divecomputer for rec diving and then having to switch to a BT for tec doesn't fall into that category.

David

[FreediveWI]

David,

Nice to have you on board over here. I don't think most people on this site know about the "120 rule", as I don't think it's been brought up here before.

The way I understand it is if your using 32% you just add your depth and bottom time to get 120. The shallower you are the longer you can stay, as long as things don't go past 120- and I am talking about feet and not meters! ;D

Of course, deep stops and slow ascents are still the norm- it still amazes me as to what some people think is a slow ascent. :

Jon

[DRE]

That's it indeed - amazing how a BT will be sufficient for all your diving needs. Also, you can use the same rule to dive 30/30 to 120ft but just subtract 20 ft from max depth (so you're using the gas exactly the same way as EAN32 to 100ft).
For those of you who are not familiar with doing deco (every dive is a deco dive and should be treated as such), check out George Irvine's description of dive profiles and ascents on

David