Where was the instructor?

[Al Mialkovsky]

Umm. Never?

In fact, in the case of any kind of failure that would require oral inflation, I'd be deflating it, because I'd be on the way back to the surface, since the dive would be over at that point.

I may be a little dense today, but I can't see this as a very useful skill, and certainly not one that needs to be in an OW class.

Terry

We aren't required to teach that skill with ssi but I do show them it in the pool but I do not include it with my open water checkouts.

 

[Ian T]

webmonkey...
i dove with rental stuff for a long time, sometimes you would get a rental reg/bcd where the connection was shot and would inflate the bcd continously...the solution was to un-hook the connection, orally inflate the bcd at depth to get neutral buoyancy and continue the dive...most of the time you inflate for neutral once or twice in a dive and then deflate it during the dive (to make up for added buoyancey if you're diving alu bottles like we do here...)... no?

 

[DiverBuoy]

Whoa after 30 minutes of reading this thread.
1.-I dont remember I orally inflated my BCD underwater in my OW.

You don't remember lying flat on the pool bottom, inflating your bc a little at a time, taking a few breaths in between to "observe" the effect of breathing in and out and how your lungs are used to fine tune your bouyancy? There are plenty of skills over the years I ask inexperienced divers about, and I'm no longer shocked to hear they can't remember doing them, but most remember something about lying flat on the pool bottom doing the fin pivot with just their breath.

 

[Chuck Tribolet]

most of the time you inflate for neutral once or twice in a dive and then deflate it during the dive (to make up for added buoyancey if you're diving alu bottles like we do here...)... no?

Maybe you inflate for neutral once or twice in a dive, but my dives tend to be multilevel,
with multiple BC (and drysuit) adjustments.

Buoyancy becomes more positive as you breathe the tank down, no matter whether the
tank is made of Aluminum, Steel, or whatever. You are removing molecules of air (or
Nitrox, Trimix, or whatever) as you breathe, so the mass of the tank goes down, so
your buoyancy goes up.

 

[DiverBuoy]

Maybe you inflate for neutral once or twice in a dive, but my dives tend to be multilevel,
with multiple BC (and drysuit) adjustments.

Buoyancy becomes more positive as you breathe the tank down, no matter whether the
tank is made of Aluminum, Steel, or whatever. You are removing molecules of air (or
Nitrox, Trimix, or whatever) as you breathe, so the mass of the tank goes down, so
your buoyancy goes up.

A rule of thumb is you lose about 1 pound of negative weighting for each 13 cubic feet consumed. While the diver is "getting lighter" over the course of the dive, typically a steel tank, a non-flexible container displaces the same amount of water weight at all points during the dive - even if it was laying next to the titanic wreck on the bottom. Steel tanks are generally negative when empty, this tends to help a bit with weighting issues.

 

[String]

But!!!........with sharing your redundant air supply or by breathing off someone elses octopus, you should not be doing an oral inflate, right???? ....dive over, correct?

If for some reason you're negative at the time you need buoyancy, especially if you have stops to do in order to avoid finning constantly to maintain a depth.

 

[Ian T]

Chuck...having seen a drysuit on postcards, I assume that inflating them orally might be a bit tricky...(c8
But even if you do multilevel, you would begin the dive at the greatest depth and as you ascend to shallower depths, you would deflate, not inflate...so no matter if it is a multi-level or square profile dive, you would only inflate once or twice, no?
Never having used a drysuit, I don't really know what the procedures are, but...
My reply was just to comment on "oral inflation not being a useful skills", that's all.
Cheers...

 

[Chuck Tribolet]

Chuck...having seen a drysuit on postcards, I assume that inflating them orally might be a bit tricky...(c8
But even if you do multilevel, you would begin the dive at the greatest depth and as you ascend to shallower depths, you would deflate, not inflate...so no matter if it is a multi-level or square profile dive, you would only inflate once or twice, no?
Never having used a drysuit, I don't really know what the procedures are, but...
My reply was just to comment on "oral inflation not being a useful skills", that's all.
Cheers...

Well, actually some older drysuits did have an oral inflation widget. I haven't seen one
in some years though.

While starting at the bottom and working up is nice in theory, it's can be difficult in practice
when dealing with rugged terrain. Some up and down becomes inevitiable, esp. if you
are a photographer.

 

[PRL]

My reply was just to comment on "oral inflation not being a useful skills", that's all.
Cheers...

This seems to be a little of topic. But I will give it a shot. Lets say you are at 100ft,
Power inflator sticks and you are at the begening of an uncontroled ascend. Being level headed and a good problem solver you disconect the LP hose to the inflator and dump the air out of your BC to arrest the ascend. Now my question to you. Are you going to dump just a little air and hope that it will be enough to stop your ascend quickly and still have enough bouancy to be able to surface with all your gear. Or are you going to dump all your air to stop the ascend and than confidently orally inflate your BC to be natural again and safely abort the dive and surface with all your gear, and not worrying about if you should call DAN or not.

Lets add to the situation. Lets say you have an expensive camera in your hand and are not near an ascend line, the bottom is still 30ft below you. Would oral inflation come in handy with compounded problems?

Hope this makes sence

 

[String]

But even if you do multilevel, you would begin the dive at the greatest depth and as you ascend to shallower depths, you would deflate, not inflate..

Not all dives are deepest first then gradually shallow. I assume he means the type of dives where your depth can increase and decrease as you go along due to the terrain.