Why use aluminum doubles for ocean diving???

[Munin]

MHK,

What is your preference for an ordinary, single dive with no logistical problems (eg remote location) where you could choose between 104s and an 80 stage? Which one is DIR? Why?

 

[O-ring]

Thanks for your thoughts. Just to make sure we are all on the same page, I guess we should see what MHK was planning as a profile for that dive. I said the Doria, so he may have been sub 200'...

Looks like we are on the same page about the need to blow air on them though...it ain't easy to bring that many sets of doubles on most boats or do mixing on the boat at 100 miles or so offshore.

 

[detroit diver]

O-ring once bubbled...

...but I could have sworn they were all wearing steels on the Brittanic dives... Come to think of it, I could have sworn I saw a couple of jon lines too..

Dave Sweetin from GUE did a really nice presentation on the Britannic dive this past weekend. Here's some of what we learned about that dive:

You did see the jon lines. The Britannic was in a VERY heavily traveled shipping lane. There was no possiblity for open water drift deco as is preferred. In fact, there were a couple of times that the freighters went DIRECTLY over the upline! The chase boats tried to ward off the bigs boys, but some just didn't care/ didn't notice. The divers said it felt like someone was thumping on their chests went they went by.....

 

[O-ring]

detroit diver once bubbled...


Dave Sweetin from GUE did a really nice presentation on the Britannic dive this past weekend. Here's some of what we learned about that dive:

You did see the jon lines. The Britannic was in a VERY heavily traveled shipping lane. There was no possiblity for open water drift deco as is preferred. In fact, there were a couple of times that the freighters went DIRECTLY over the upline! The chase boats tried to ward off the bigs boys, but some just didn't care/ didn't notice. The divers said it felt like someone was thumping on their chests went they went by.....

...I wasn't criticizing the use of jonlines on those dives. I think jonlines have their place and are an extremely important tool depending on the conditions. Just one of those instances where I wasn't sure what DIR protocol on those was and was curious since I had never seen or heard of them being used by any of the GUE folks before.

 

[WYDT]

WreckWriter once bubbled...

How do you rig the bottles for this? Surely not a standard stage rig? Doesn't seem there would be room on one's left side for 3 80s. I've seen one 80 and 2 40s slung and that appeared a major PITA.

Hi Tom,

I don't speak for Mike but the way more than two AL80's (or other stages) are carried is to clip off two like normal (left side d rings) then hip clip any more. I also doubt that Mike would be "swimming" on this dive. Probably using a Gavin, making carrying multiple stages that much easier.

It's also important to have the right AL80's (luxfer) and a He mix so they aren't too heavy.

You would be amazed how easy carrying multiple stages is when it's done correctly.

DSAO!

 

[WreckWriter]

WYDT once bubbled...
I don't speak for Mike but the way more than two AL80's (or other stages) are carried is to clip off two like normal (left side d rings) then hip clip any more. I also doubt that Mike would be "swimming" on this dive. Probably using a Gavin, making carrying multiple stages that much easier.

It's also important to have the right AL80's (luxfer) and a He mix so they aren't too heavy.

You would be amazed how easy carrying multiple stages is when it's done correctly.

DSAO!

Hi Rob,

When you say "hip clip" I assume you mean clip the forward snap to the hip d-ring? Are you using standard stage/deco rigging on these bottles or something else? This is not something I've seen done, I'm guessing its more of a cave technique?

Sure, I would also presume riding a Gavin (beats the heck out of swimming). I was think more about out of the water movement. I guess one could possibly get assistance as far as moving around on the boat but that's not really something we're used to around here.

Once on the wreck one would, again I'm assuming here, remove at least some of the stages for one's penetration? It sure seems a lot to go through for a dive that I would consider double 104s and two 40s perfectly adaquate for.

Thanks for your reply.

Tom

 

[WYDT]

WreckWriter once bubbled...


Hi Rob,

When you say "hip clip" I assume you mean clip the forward snap to the hip d-ring? Are you using standard stage/deco rigging on these bottles or something else? This is not something I've seen done, I'm guessing its more of a cave technique?

Sure, I would also presume riding a Gavin (beats the heck out of swimming). I was think more about out of the water movement. I guess one could possibly get assistance as far as moving around on the boat but that's not really something we're used to around here.

Once on the wreck one would, again I'm assuming here, remove at least some of the stages for one's penetration? It sure seems a lot to go through for a dive that I would consider double 104s and two 40s perfectly adaquate for.

Thanks for your reply.

Tom

Yes, these stages are rigged normally and the top clip is clipped to the left d ring on the belt. I agree that I couldn't really see penetrating a wreck with more than one stage... you could drop extra stages (deco, etc.) at the entry point on the line, assuming you were coming out the same way. This is speculation and I fear I'm overstepping my bounds here. I haven't done any dives on the doria and am speaking mainly of what we do cave diving although I know a lot of GUE/DIR do deep wrecks the same way.

Just trying to explain the rationale...

 

[WreckWriter]

WYDT once bubbled...


Yes, these stages are rigged normally and the top clip is clipped to the left d ring on the belt. I agree that I couldn't really see penetrating a wreck with more than one stage... you could drop extra stages (deco, etc.) at the entry point on the line, assuming you were coming out the same way. This is speculation and I fear I'm overstepping my bounds here. I haven't done any dives on the doria and am speaking mainly of what we do cave diving although I know a lot of GUE/DIR do deep wrecks the same way.

Just trying to explain the rationale...

Yea, gotcha on that. One of my primary reasons for using back gas and two smaller tanks is to avoid dropping my deco bottles. Admittedly there are situations where it would be acceptable (i.e. line penetrations) but I like the option of taking a secondary exit should the need arise.

I haven't dived the Doria either but have done a few wreck dives in this depth range.

You're certainly not overstepping your bounds, I'm looking for your opinion, not policy statements

Tom

 

[WYDT]

WreckWriter once bubbled...


Yea, gotcha on that. One of my primary reasons for using back gas and two smaller tanks is to avoid dropping my deco bottles. Admittedly there are situations where it would be acceptable (i.e. line penetrations) but I like the option of taking a secondary exit should the need arise.

I haven't dived the Doria either but have done a few wreck dives in this depth range.

You're certainly not overstepping your bounds, I'm looking for your opinion, not policy statements

Tom

Thanks Tom,

I'm trying to explain what I DO know with out sounding like a "know it all" because I certainly don't know it all... especially when it comes to deep ocean diving.

I do see where stages could be great if only one set of doubles were allowed on board the boat but I agree that they would take up nearly as much space as two sets of doubles.... the one major factor in using stages is that you always have a big reserve (backgas) that may ease your mind when ****e hits the fan at 200+ inside a wreck. One way to get stages on/off without having to carry them above water is to hand them off once in the water or clip them to a line attached to the side of the boat. This would depend on seas and current but that's the way I'd do it! Especially coming out of the water you don't want to be working too hard.

 

[ericfine50]

Mike

Was this a Seeker Trip? I think I saw a picture of you on Christina's site. Did you not use a hood?

Eric