Air in BC? What do you do?

[trigfunctions]

I think you should have air in your BCD before jumping in for a couple of reasons. It is a way to check to make sure your air is on and your BCD is working properly and not leaking. Also, if you jump in and crack your head on something or someone jumps on top of you and their tank hits your head (or if something less severe happens like your mask pops off) you want to be floating at the surface instead of sinking.

 

[spectrum]

On a boat you want to bob up after entry. This will let you make a final check & sync up with your buddy & OK the bpat. If that means air in your BC then add some.

On a shore dive I almost always add some. That way if I slip on a rock I know I'm not going down. If the footing is of real concern the regulator is in the mouth too. Since we often start with a surface swim to descent depth we need the lift with cold water suits & weights.

You can add it oraly to conserve tank air and it should dump in a flash so why not?

Pete

 

[Damselfish]

Lots of good thoughts. I would just add a general comment - some of the rules you are taught in class are just a reasonable way to start, and some will apply more to the conditions you were training in. You will learn to modify what you do in different situations as you get more experience.

I usually do not have air in my BC when I jump in, but it depends on the situation. I have found one unmentioned advantage of having some air in there - staying on the surface when I splash is easier on my fussy ears, rather than a quick submerge (even though it may only be a few feet) followed by popping up.

 

[Web Monkey]

Unless there's a really good reason not to (a few special conditions require a "hot" entry) and the DM has told you to do so, you should inflate your BC before getting in the water.

There are a number of good reasons, and this list is not exhaustive:

• Proves that your air is on (at least partially)
• Proves that your BC will hold air
• Gives you a second chance to make sure your reg is breathable.
• Gives you a chance to get with your buddy before descending

You should actually cover the first 3 in your pre-dive check before every dive, but in case you screw up, it gives you one more chance. Jumping in negative with your air off, for example, will give you an extremely short amount of time to discover if you can reach your tank valve or not.

Terry

Hello,

This is a strange question and I'm curious as to what most of you do.

When I was trained for OW certification, I was taught to enter the water with a full BC and then let the air out to decend. Well, then for my AOW certification, I noticed that the Instructor and (other experienced divers) entered the water with no air their BC. Since then, I've noticed other DM and divers who would enter the water with no air in their BC and I've started doing the same.

 

[Wildcard]

You don't even need to inflate it all the way, just 1/3-1/2. It's a safety thing and it's worth doing. Keeps you on the surface, just in case.

 

[TSandM]

If you jump in with no air in your BC, do you have to swim up to stay on the surface? If not, if you just float there with ease with an empty BC, that would worry me a lot that you are underweighted for the end of the dive. You may not have realized that, if you never breathe a tank down below 1500 psi. I have the same situation a lot of the time . . . I dive a 95 and very, very rarely surface with less than 14 or 1500 psi. So, since I'm weighted to be neutral at 5' at 500, I'm negative and carrying air in the BC through the whole dive. I keep thinking I could take some weight off, but then, if for some reason I end up using more air on a particular dive, I could have trouble holding a stop at the end. So I stay weighted the way I am.

 

[Eagle-scuba]

you have to determine the conditions you are diving in, wether it requires additional air in the bc to keep your head up and out, most blue water divers I know, add some air to the bc before entries, as a precautionary measure, it can always be released after entry. As for additional weight and trying to compensate with air , that is what novice divers might do, while determining bouyancy...but you sound quite skilled in knowing your bouyancy control, maybe you would be better off trying different methods, and find one that works best for you...I perfer to add a little more air at the beginning, when doing a giant stride, especially from large vessels, like at flower gardens, where the drop from deck to water can be upwards of 7ft on a good day, and more if the seas are rolling, this helps keep me from going under too deep, and possibly getting under the boat during rough sea entries... See ya` under

 

[serambin]

I inflate my BC about 1/4 full and prefer to be 2 -3 lbs heavy on weights at entry. With a giant stride entry, if I do it right, the top of my head stays dry. As others mentioned, this allows for compensation for positive bouyancy as my tank empties.

Years ago, I had a strap failure on entry from a platform on the stearn of a large boat. The tank valve struck me in the back of the head hard enought to stun me for a few seconds. I aborted the dive, but my BC insured that I stayed on the surface while I watched the stars clear.

The habit of working for a shallow entry is important in diving poor vis lakes and brackish bayou waters. You can't see what you're landing on, so you can't afford to go very deep.

Stan

 

[Diverblam]

Wow... thank you everyone... I will definitely start putting air in my bc... for the #1 reason listed which also scared me the most: in case something knocks me out! You guys taught me a lesson... thank you.

TSandM: You're correct, I do need to kick my feet to stay float on the surface, but its not for long. My buddy is either already in the water or is the next one in. We stay long enough to check each other out and descend. I was also able to breath my air down to 500 psi one time and did have to work hard at staying at 15'. I'll probably add another pound then... I hope that I have more opportunities to stay down longer!

Thank you everyone. =)

 

[Nemrod]

"Nope... all are boat dives... giant strides or backwards roll... doesn't matter... I only sink like 5-10 feet when I jump in (depending on current) and just kick to the surface after my jumps. "

"On a boat you want to bob up after entry."

While this is commonly taught it is generally detrimental. Often there are strong currents that dissapate rapidly within ten to twenty feet of the surface. Time and time and time again I have watched new divers inflate their BCs and like lemmings march over the side only to be swept away as they struggle and flail and vomit and flail some more usually ruining their dive. Meanwhile those who "Roll and Go" have a great dive. I hit the water, BC sucked flat empty (if I even have one) and I am gone, while your bobbing on the surface checking your valves and widgets for the fourth time I am already past 60 feet and the boat is a memory and I am also usually the last one back. That is just me though. Air in the BC, why, are we going diving or are we going floating? N