Skin diving around divers on a safety stop

[Papa_Bear]

Real divers know you blow! Do you mean like this?

 

[24940]

Thanks for proving my point.

 

[nannymouse]

I see people post about "bubbles being compressed enough to transfer from the vienous side to the arterial side. Since the flow will be away from the capillaries, I would not think that the transfer would be there. The veins return to the heart and the blood is pumped into the lungs via the pulmonary arteries, where it does the CO2/O2 exchange. The pulmonary veins return the blood to the heart where, aside from the coronary arteries, the blood vessels get smaller and smaller.

Can freediving compress the bubbles enough to be carried through the lungs?
What if the bubbles lodge in the pulmonary arteries?

Should the freediver do a 3 minute safety stop at 15 feet?

 

[fdog]

After a dive (especially one with significant deco obligation) the body sheds bubbles into the bloodstream. This process happens for a significant time after surfacing. It still happens after a recreational dive, albiet to a smaler extent.

You can simulate this by opening a 2 liter bottle of soda. As we all know, bubbles are generated as you slowly open the lid; but, when you finally get the lid off (the point you'd surface at) you can observe the bubble production continues for quite some time.

These bubbles are usually filtered out by the lungs, and never make it into the arterial side. Bubbles that are small enough to make it through, are small enough that they will not occlude cappilaries elsewhere, and thus unlikely to generate DCS.

Here's the part that concerns us about skindiving immediately after a dive:

• Your body is shedding bubbles.
• You dive to 15'-20'.
• Fairly largish bubbles (generated on the surface) compress.
• They become small enough to get through the lungs.
• You surface.
• They expand, now in the arterial side.
• They get circulated to something vulnerable, and you get DCS.

Obviously there's lots of variables here - what your obligation was, your cappilary lumen size, bubble production rate, etc. Regardless, it's adding a risk you don't need to.

And breathing off the octo is a whole other set of risks you shouldn't have to endure as well.

All the best, James

 

[Papa_Bear]

You know it boils down to this, is there any evidence that anyone anywhere has ever had a hit from this kind of activity? NO! So dive in and have some freakin fun! As long as you exhale on the way up and you haven't done a deco dive what is the big deal? Really does anyone just ever have fun? It is a safety stop, not a required deco stop! Again show me some stats showing this to be dangerous! Lets all go diving and have some fun!

If you don't want to be a part of this kind of play wave the person off and they will return to the surface non the worse for wear If your working on a rig and someone does this to you report them to the safety officer! :11:

 

[sheck33]

Yes, your girlfriend should have scolded him for all of the reasons stated above. However, what is she (or her buddy) doing giving up her octo to this clown. Divers are taught to never let someone grab a regulator. No one should ever touch your reg or octo unless you offer it. You might want to scold your girlfriend for that if it was offered. Letting a clown get that close to you while offgassing is dangerous (as well as encouraging his foolishness). You don't know if he is suddenly going to drag you up to the surface in a rapid ascent.

That is news to me. As far as I am aware, at least in the classes I help out with, new divers are told that an OOA diver might grab their primary regulator in panic and they should be prepared for that. That is why we donate our primary reg to begin with, that way the OOA diver is guaranteed to get a working regulator.

 

[sheck33]

You know it boils down to this, is there any evidence that anyone anywhere has ever had a hit from this kind of activity? NO! So dive in and have some freakin fun! As long as you exhale on the way up and you haven't done a deco dive what is the big deal? Really does anyone just ever have fun? It is a safety stop, not a required deco stop! Again show me some stats showing this to be dangerous! Lets all go diving and have some fun!

If you don't want to be a part of this kind of play wave the person off and they will return to the surface non the worse for wear If your working on a rig and someone does this to you report them to the safety officer! :11:

For deeper dives this is not true. Free diving after deeper dives is NOT a smart thing to do and carries a high risk of bubbling. And every dive you do is a decompression dive, the very reason we do minimum deco even for dives that are not considered 'deco dives'. And it makes a difference in how I feel after a dive. This is true even for
dives that are not extreme by any stretch of the imagination.

 

[Bob Vincent]

As a diver who likes to skin dive whenever too N2 loaded or before flying, I understand wanting to hop back in the water (and wanting to borrow an octo).

Breathing from an octo at a shallow depth is not a problem if you know what you are doing, i.e. don't hold your breath on the way to the surface and plan enough breath to get back to the surface.

In addition, the water is shallow enough that the little extra N2 loading would be insignificant compared to the dive the guy just finished.

Now, as for the seal/sealion analogy, if some skin diver dove down and requested to borrow my octo, I don't think I would let him simply because he might not know what he is doing.

Also, if he was really doing the whole sea lion thing, it does come across as rather immature. I dive to see fish, coral, and the underwater environment (pictures too!) but not to see some dude playing sea lion during my safety stop.

YEPPERS!

 

[stefo2]

Breathing from an octo at a shallow depth is not a problem if you know what you are doing, i.e. don't hold your breath on the way to the surface and plan enough breath to get back to the surface.

True. But we just learned that this guy was a novice diver, so I would rate the danger of the "hold-your-breath-instinct" after taking a breath at depth as quite high.

 

[String]

Divers are taught to never let someone grab a regulator. No one should ever touch your reg or octo unless you offer it.

No they aren't - its completely the opposite.
Divers are taught at open water/basic level TO take the octopus after first signalling. Under PADI only when you get to rescue diver do you think about donating it to them as opposed to letting them take.
Plus if someone REALLY needs air and you're expecting them to wait while you find, unclip, orientate and donate an octopus you're living on a different planet - i can guarantee they wont sit and wait patiently for that - they WILL make a grab for it.

You might want to scold your girlfriend for that if it was offered. Letting a clown get that close to you while offgassing is dangerous (as well as encouraging his foolishness).

That's the clowns problem not the other persons. If they want to take a risk that's their choice.

Personally ive done an entire dive with no gear holding onto someone using their octo purely because i wasn't meant to be diving that day but conditions were unusually good so i borrowed a suit, some weights and just held on for the ride.
Unconventional? Possibly. Dangerous? Possibly. My choice entirely? Yep.