DIR/GUE - No steel stage bottles

[divengolf]

I recently read on the GUE site that they do not permit steel stage bottles. Can someone enlighten me as to why this is?

I know that they are neg. bouyant, but this can be handed with weight adjustment as needed.

 

[Bismark]

I recently read on the GUE site that they do not permit steel stage bottles. Can someone enlighten me as to why this is?

I know that they are neg. bouyant, but this can be handed with weight adjustment as needed.

And you have 40 minutes of deco and you lose a stage or two............

Have you ever tried to carry multiple steel tanks as stages?

 

[String]

I know that they are neg. bouyant, but this can be handed with weight adjustment as needed.

Realistically its not a big difference. A steel 7l is maybe 1-1.5kg or so negative and thats it. Until you start carrying 3 or 4 its not an issue.

..but as this is the DIR forum - no they wont let you use steel.

 

[SparticleBrane]

..but as this is the DIR forum - no they wont let you use steel.

"won't let you" is pretty strong. There's no scuba police. Obviously they "won't let you" use them in GUE classes, but every scuba course has equipment requirements...


"Don't agree with" and "voluntarily don't use" might be better word choice.

 

[Gombessa]

every scuba course has equipment requirements...

Sigh, wanna buy the snorkel they made me get during OW class?

 

[SparticleBrane]

Sigh, wanna buy the snorkel they made me get during OW class?

I was actually thinking of some hoses.

 

[nadwidny]

I recently read on the GUE site that they do not permit steel stage bottles. Can someone enlighten me as to why this is?

Because they hang like anchors.

I know that they are neg. bouyant, but this can be handed with weight adjustment as needed.

One of the funniest things I've ever seen is some guys that dove with steel stages/deco cylinders. We did some dives with them and when they saw how much better the aluminum cylinders rode and how much better the trim was when carrying multiple Als as opposed to steels, they tried to compensate by filling the tank boot of their steels with that spray foam stuff used to fill cracks in houses. And yes it worked about as well as it sounds. The GIII response was classic.

Yes, steels can theoretically be handled with weight adjustment but real world experience beats out never-ever theory every single time.

 

[nilsdiver]

"won't let you" is pretty strong. There's no scuba police. Obviously they "won't let you" use them in GUE classes, but every scuba course has equipment requirements...


"Don't agree with" and "voluntarily don't use" might be better word choice.

Really??? I was under the impression WKPP was using steal stages for O2.

 

[MonkSeal]

Realistically its not a big difference. A steel 7l is maybe 1-1.5kg or so negative and thats it. Until you start carrying 3 or 4 its not an issue.

..but as this is the DIR forum - no they wont let you use steel.

Have you ever tried to carry few of them? How did they ride? It's not a question if someone lets you something - it's common sense issue in whole picture when one carries stages on left side and on the leash.

 

[DIR-Atlanta]

I was under the impression WKPP was using steal stages for O2.

It's true that larger steel cylinders (72s, 95s, etc) are a common choice for longer oxygen deco. However, these bottles are not "carried" in the same sense that a stage bottle would be. The O2 bottles are normally placed at the final stop depth and then left there for when the divers exit. So the issue of weight and buoyancy are not really relevant. Also, the LP steel cylinders are a good choice for this application, as they are closer to "full" at the pressures that one typically gets from an O2 cascade (i.e. more volume of available gas at the lower pressure). Yes I know you can boost the O2, but why bother if you don't have to?

A true "stage" bottle is carried for some distance into the cave, so its buoyancy characteristics are important. The bottle should not hang below the plane of the divers body, so negatively buoyant stages are not recommended. Aluminum cylinders are generally neutral to slightly positive (especially when used with helium-based mixtures), and so they "hang" (and therefore travel) a lot better, particularly when scootering. Aluminum cylinders also tend to float when "dropped", which can be a consideration in systems that have silty floors - clip the bottle to the line at a stage drop, and it will float away from the bottom.

For those reasons, aluminum cylinders are the preferred choice for stage bottles.

EDIT: As noted in RTodd's response here, this advice applies specifically to cave dives, where O2 bottles are typically dropped early on in the dive.