DIR lesson 2

[kramynot2000]

Originally Posted by [b

Quote[/b] (Dominic @ Sep. 03 2003,05:47)]Buddy wings do - on the left.

I'm skeptical about that really being the DIR way of doing it tho - DIR twinset wings aren't linked at the bottom, they DO trap air at the sides - if you use the bottom dump, it'll only dump the air on one side. Going slightly upright and using the central corrugated hose makes a lot more sense..

If you go to http://www.fifthd.com/classinfo/video/ascents.htm and watch, you'll see that the first thing the guy on the right does is use his corrugated hose to dump air.
He does eventually use the bum dump, but it's a bloody awkward contortion he has to do to use it - I'll stick with the hose.

I know this is the way Mike Kane teaches it as my use of the corrogated hose to dump air was "commented on" during class.  A buddy of mine just went through Rec Triox and got the same instruction.

Since taking the fundamentals class I started using only the rear dump and like anything (golfing for example!) it was extremely awkward.  However, now I don't even think about it and only use the corrogated dump for the initial 2' or so of ascent and then its strictly rear dump.

The air does trap on horseshoe wings so every once in a while, you have to go head up and then back down to horizontal to redistribute the air between the two sides of the wings.

Tony

[Lou]

So why not use the corrugated hose then?  If the reasoning to use the bum dump is that the hose is not always the highest point and thus wouldn't let you dump all the air, but the bum dump doesn't either, then surely there isn't any advantage?

What I really can't understand is why the other wings have the bottom dump on the front.  I thought I must have set it up wrong at first, hence checking other wings in the shops, but alot of them were the same.

[Dominic]

So... what's the big advantage??

Either - Go momentarily upright and dump from the hose - all air dumped at once equally from both sides

OR - Dump air from the bum dump, leading to unequal air distribution, fixed by going momentarily upright

What's the great benefit here? Either way you have to go momentarily upright, but one will screw your buoyancy and the other won't. I can't believe they're THAT desperate to keep salt water out of the wing...

Lou - I think it's so you can reach it easily - if it's on the cylinder side, then when the wing wraps, the dump is actually pressed against the cylinder. T'other way means it remains free and unrestricted so you can reach it & let air out easier.

[kramynot2000]

Dominic,

Actually its not as bad as that.  Only occassionally do I have to redistribute air between the sides of the wings because the amount of air being dumped is actually not that much.  On some dives, especially those with a relatively flat bottom profile, I don't have to do it all.  I really don't notice an imbalance in the wings until it gets really bad then its just a quick tip up and down and all air is adjusted.

While swimming on the bottom, I find it very easy (now that I'm used to it) to maintain horizontal trim and adjust up and down remaining horizontal.  I didnt' think I'd actually like it, but now I'm kinda hooked on using the rear dump.

Tony

P.S.  I really like the pack you made for your backplate!  As soon as I get back from my trip to the Isle of Mull and Manchester (leaving tomorrow!!!!) I'm gonna try to copy it.  You know what they say, imitation is the sincerest form of flattery!

[Ian Murray]

Originally Posted by [b

Quote[/b] (Lou @ Sep. 03 2003,10:40)]Why have the main on your right?  I have never understood this, it seems counter intuitive to me.  Is it because you raise your inflator hose on the wing to dump?

Lou

Lou,

The Lighthead is held in the left (back) hand. So the gague goes on the right wrist. It can then be viewed with the torch if necessary without having to swap hands with the torch.

Also, not really relevant to your posting but I think that if you were using a scooter then the left hand is used to 'light the way' with the light head and the right wrist can be monitored more easily in the scootering position for depth, time etc...

Regards, Ian.

[Bob Cooper]

Originally Posted by [b

Quote[/b] (Ian Murray @ Sep. 03 2003,17:56)]

Originally Posted by [b

Quote[/b] ]The Lighthead is held in the left (back) hand. So the gague goes on the right wrist. It can then be viewed with the torch if necessary without having to swap hands with the torch.

That's right..

Originally Posted by [b

Quote[/b] ]Also, not really relevant to your posting but I think that if you were using a scooter then the left hand is used to 'light the way' with the light head and the right wrist can be monitored more easily in the scootering position for depth, time etc...

That's right too...

This is really easy since the Uwatec dive timer can be seen at any angle, unlike some computers, especially the Vyper!

I like to carry a Vyper since it acts as my dive log, using the download option.  I use it in gauge mode of course!  Some people keep them in their pocket for the same reason.

I know some cave divers who don't carry ANY kind of depth gauge or timer (this isn't DIR by he way).  They KNOW the cave, they KNOW the depths and they KNOW how long they spend at depth, given the flow of the cave and their speed.

[Pierre Farrugia]

<font color='#0000FF'>Hello,

This is one thing that don't like from DIR, is have to adhere to a strict set up and tell you why. I use a Vytec and a promaster watch bottom timer. When I do serious staff I cut tabels with bottom and deco gas, then follow tabels all the way BUT have my vytec with gas swithces as a backup. I find the vytec to be +\- 5min from tabels. Will do all deep stops frp, proplanner and tabels. My big question is, do you do only deep or deco dives? As tabels are great for wrecks or square profiles but shore dives is an other story. Also I would have my buddy's comp as back up and even tabels if my comp. go down , my buddy is lost or both computers are down which never happened in 10 years diving. Not using a comp. you don't understand deco theory, at the end you will only know a little bit about it as only the one who wrote the programme will understand it. At least me will have something to compare with while under water.
Also why someone has to tell you from where you dump air from wing...is this too much. You can dump air from hose in horizontal position and a couple of seconds wouldn't foul your profile.

Regards

Pierre farrugia

[Lou]

Again I must be cack handed because my torch always goes in my right hand - I'm doomed!!

But the logic of torch in left hand comes from scootering, so right wrist computer comes from scootering, and hence I'm probably not going to encounter too many problems doing it the &quot;wrong&quot; way round.

Cheers for the info

Lou

[Dominic]

Originally Posted by [b

Quote[/b] ]I really don't notice an imbalance in the wings until it gets really bad then its just a quick tip up and down and all air is adjusted.

I'm sure it's not that bad - &nbsp;I just don't see what the benefit is - if you have to tip upright occasionally anyway, what advantage does using the bum-dump give?

Obviously, in my Stroke wing, it's a non-issue, as air is free to migrate, but with a proper DIR one it seems to be creating a problem without giving a visible benefit. Does the Halcyon inner bag dislike salt or something?

Good luck with the backplate pack. Are you doing it in the same purple colour?
Finally got a shot of it from the front on the web page, by the way - updated yesterday.

[Dominic]

Originally Posted by [b

Quote[/b] ]The Lighthead is held in the left (back) hand.

Mine isn't. When it's assembled and taken underwater, that is

I daresay it SHOULD be, as my instruments are on the right. But I don't like the cable going across my front.. besides, my computer is on the left, and it has a backlight