Dumping Air Under Water

[Litefoot]

I think this can be put in the solved colum;
use which Eve dump works best for YOU!

I think you’re right, but I learned a lot here. So thanks everyone for your great insights. And we stayed on topic for 5 whole pages. Is that a record?

 

[wetb4igetinthewater]

Six pages in and no one brought up the Axiom i3 with the little lever?

I'll see myself out

 

[Chavodel8en]

I guess Im weird bc I use both - kidney dump or inflator hose. Just tilt up or down and dump. Takes 3 seconds either way.

 

[Doc Harry]

....due to an injury to my left shoulder.

Glad to hear that it hasn't kept you from diving.

 

[Divin'Papaw]

Six pages in and no one brought up the Axiom i3 with the little lever?

I'll see myself out

Bwawahah! I completely forgot about those. Do they still exist??!!

 

[wetb4igetinthewater]

Bwawahah! I completely forgot about those. Do they still exist??!!

I got one for teaching rescue for throwing off my students. While Up here people dive BP/W and jacket style BCDs, some dive sidemount. I've never seen these being used, but I use it as a teaching tool to get people to think.

 

[wetb4igetinthewater]

How's your trim in a jacket BCD compared with a BP + wing?

So the correct answer is that it depends on a number of factors.

This is NOT a skills issue. We all know that correct weighting is the amount required to hold a safety stop and ascend under control to the surface with an empty wing/BCD and in the case of wearing a dry suit, only enough gas to provide sufficient warmth and comfort.

Weight distribution is a key part of proper weighting. Weight distribution must address the difference between the center of mass and the center of volume/displacement.

Most people tend to be foot heavy. It is simple physics. No skills involved.

Exposure protection plays a huge part obviously. Shorty wetsuits exacerbate the issue. And I am seeing this here in Cuba. The only diver in trim was a woman who brought her BP/W with her. None of the guides or other customers were in trim.

So onto equipment. Do jacket style BCDs have two cylinder straps? I'm seeing better the cheapest possible BCDs. Single strap, no trim pockets. Additional weights go into the waist pockets. I wish I brought some bungee to mount the two 1-kilogram weights to the top parts of the shoulder straps.

It is pure delusion to expect dive centers in poor countries to buy the most expensive jacket style BCDs that are more expensive than Had Some Money Once (Halcyon).

I wish these places would use inexpensive aluminum backplates with inexpensive webbing. And some inexpensive trim pockets.

Cost wise it would likely be the same, probably save them money over the long haul. And the reefs would REALLY appreciate it.

This is a really basic physics issue that should be covered in open water. But due to indifference, ignorance, or incompetence, it isn't.

 

[BlueTrin]

You must be diving with a ton of air in your wing, or you swim in the vertical position.

I cannot vent from my inflator hose when it's stored in the bungee, and in no way can the bungee stretch far enough to get my inflator hose high enough to vent when I'm horizontal.

Even if I didn't store my inflator hose, I can still vent much faster and easier from the rear valve.

If I go slightly in heads-up trim and raise the inflator like if I was trying to raise/curl it behind my neck rather than raising up and forwards, then, it works with my wing.

In fact for me it seems to work in flattish trim … but I concede I may be negative in my default config.

 

[Doctorfish]

Who would have thought that something as seemingly simple as dumping air would stimulate this much discussion. We must all have nothing else to do.

 

[Wibble]

Who would have thought that something as seemingly simple as dumping air would stimulate this much discussion. We must all have nothing else to do.

Waiting for the season to start. Only another four weeks…. to the first potential cancellation due to foul weather

A nice reasonable sized 1970's wreck at 40m/130ft for a couple of hours of hydrobaric therapy.