Air in BC? What do you do?

[Diverblam]

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.

Now... is this ok? Is it standard? I'm neutrally bouyant with the weights that I have, can decend / accend with no problems at all and can control my bouyancy.

Or is it better to put on a bit more weight and therefore require the need to put air in my BC to adjust my bouyancy?

Thoughts?

Thank you.

 

[BabyDuck]

i didn't need air in my wing in a single to float on the surface, but i do in doubles. my opinion would be *not* to add weight just so you can add air. if you can float when you want, sink when you want, and hold a safety stop, i'd say you're perfect.

 

[www.scubamazing.com]

Maybe it depends on the method of entry. I'd think in your situation, you'd be fine with or without air in you BC, if you were doing a shore entry into calm water-- which probably would have been the conditions your course was in.

However, in rougher conditions or doing a giant stride entry, I'd think you'd want air in your bc.

I agree though adding weight to add air is kind of pointless, it could even make you breathe your air faster. I congratulate you on having your gear & weights down to a science so that you start out neutral.

 

[David The Gnome]

I was taught by my dive master that you should always inflate your BC so you don't kick up any silt under the water when you jump in. If you were diving off a boat in deeper water I would still keep some air in there. You don't want to risk accidently being over weighted and sinking like a rock as soon as you jump in.

 

[Diverblam]

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. Yep... can stay at 15 feet for my safety stop with no problems. I also consume my air very slow... at the end of a dive, I'm usually the last one out of the water and will have double the amount of air than 99% of the others (Doesn't matter if the others are men are women... I still have double the amount of air in my tank.) I've only met two other women who would surface with about 200 psi less than me (at least on this last dive trip). Sadly, by the time we get back to the boat and hang out below, I usually hit my 1500 psi turnaround alarm.

Thanks... I didn't think about air consumption by adding more weights and more air...

 

[Packhorse]

I always enter the water with my BC full of air. Although I mainly float my BC in the water then jump in and then put my BC on. This has more to do with the size of the boat and ease of getting geared up.

 

[Diverblam]

Interesting Packhorse! I haven't had to try that method yet... almost did when we had to dive off a village boat instead of a regular dive boat... that was an experience. =)

Err... like your quote too... =)
B

 

[David The Gnome]

They made us take off our BCs and put them back on in the water during our training and check out dives at my training center. The first time I slipped out of my BCD I forgot about my weight belt being on and I sank like I rock for a second before realizing what was going on and swimming back to the surface. I felt so dumb after that lol. Lesson learned though, now I have a BC with integrated weights, shouldn't be a problem anymore.

 

[kidspot]

If doing this for boat dives I would always add air, if even a little, this gives me another confirmations (one of many) that my air is on and I'm good to go.

Sometimes when doing drift dives where they do a live drop a boat will have you wait at the bottom and not at the top getting carried away while waiting to group up. In that case I add a little air to my wing, hold the exhaust valve open and jump in, allowing all the air to vent and a quick descent to where we will meet up on the bottom. I add air as a matter of consistency in verifying my air again, even when I'm going to let it out right away.

For shore entries, if it's calm and I have a surface swim I put air in. If it's rough and I need to drop quickly and swim under the waves, I'll put my fins on before entering the water, reg in mouth, bc empty - swim out under the waves and meet up on the other side of the breakers - inflate and wait at the surface to make sure the team made it safely through, then start the dive.

Aloha, Tim

 

[WaterWolf]

When you start your dive, your buoyancy should be slightly negative in order to maintain neutral buoyancy after you breathe some of the air out of your tank, since your tank becomes more buoyant as you consume the air.

If you are entering the water with neutral buoyancy and there is no air in your BC, you could you could find yourself ascending as your tank empties and there will be no air to release in your BC to maintain neutral buoyancy.

With that said, I would say that you need at least a little air in your BCD if you are weighted correctly.