Which hand do use to hold the spool/reel when inflating the DSMB

[BlueTrin]

I used the right hand to hold the reel and DSMB because I thought I can inflate deflate air from my wing if needed with the left hand.

Then I was wondering: if I use my drysuit for buoyancy does that mean I need to do the opposite ?

 

[CptTightPants21]

When just starting out, you should be neutrally buoyant when you deploy the bag. People can have a personal preference when setting up, but typically the reel and bag will be held in your left hand when you are ready to inflate. Your right hand will remove your 2nd stage regulator while the left brings brings the DSMBs inflation nozzle to your mouth to be filled with your exhale. Depending on depth and lung volume, one full exhale will generally be enough to get the bag where it needs to be before Boyle takes over on it's way up. A 2nd exhale may be needed and the bag may start to pull you up a little. This is corrected by either kicking down slightly or dumping a small poof of air from the wing between exhales, remember to add a poof of air (or a deep breath with your lungs) after the bag is released.

Drysuit shouldn't be your primary buoyancy and doesn't have a bearing on the question. From my experience, a drysuit will have plenty of air in it from your initial ascent and if anything might need to have air released rather than added. As you ascend up the smb, the drysuit should be the first thing you attempt to drain. It is much easier to correct buoyancy (add or subtract air) with a wing than with the drysuit so the air in the drysuit should be the first thing you try to remove from the equation.

Other hints when first starting out:
1. Have a buddy and a set reference point
2. Check your depth after each step
3. A few videos below

 

[Graeme Fraser]

Whichever feels more natural. I'm right handed but prefer to hold the reel / spool in my left for shooting the blob. No particular reason, I just prefer it that way. If I'm doing deco I sometimes switch a) for wing lpi, b) something do do.

If you're just doing rec and using drysuit only for buoyancy it makes no difference as the valve can usually swivel. Worth having a slightly longer inflator hose though for detaching the hose inflating the bag away from your body.

 

[BlueTrin]

Whichever feels more natural. I'm right handed but prefer to hold the reel / spool in my left for shooting the blob. No particular reason, I just prefer it that way. If I'm doing deco I sometimes switch a) for wing lpi, b) something do do.

If you're just doing rec and using drysuit only for buoyancy it makes no difference as the valve can usually swivel. Worth having a slightly longer inflator hose though for detaching the hose inflating the bag away from your body.

I thought it would be harder to release air from the drysuit if I start to ascend by mistake with my left hand. This is why I was wondering. (valve is only a few clicks from open but still)

Thought this video was interesting:

 

[Graeme Fraser]

I thought it would be harder to release air from the drysuit if I start to ascend by mistake with my left hand. This is why I was wondering. (valve is only a few clicks from open but still)

Thought this video was interesting:

His videos are very good. I'm a bit of an avid fan of his Friday YouTube vids.

Slightly raising your left shoulder should be enough to vent any excess buoyancy. Also if you do get dragged up by a bag, just let go. For some reason people often grab hold for dear life . Embarrassing but we've all bolloxed up a blob shoot before. Just suck up the shame and hope the skipper picks it up topside.

 

[1atm]

When just starting out, you should be neutrally buoyant when you deploy the bag. People can have a personal preference when setting up, but typically the reel and bag will be held in your left hand when you are ready to inflate. Your right hand will remove your 2nd stage regulator while the left brings brings the DSMBs inflation nozzle to your mouth to be filled with your exhale. Depending on depth and lung volume, one full exhale will generally be enough to get the bag where it needs to be before Boyle takes over on it's way up. A 2nd exhale may be needed and the bag may start to pull you up a little. This is corrected by either kicking down slightly or dumping a small poof of air from the wing between exhales, remember to add a poof of air (or a deep breath with your lungs) after the bag is released.

Drysuit shouldn't be your primary buoyancy and doesn't have a bearing on the question. From my experience, a drysuit will have plenty of air in it from your initial ascent and if anything might need to have air released rather than added. As you ascend up the smb, the drysuit should be the first thing you attempt to drain. It is much easier to correct buoyancy (add or subtract air) with a wing than with the drysuit so the air in the drysuit should be the first thing you try to remove from the equation.

...

I do it this way too, except that outside tech classes I already have the spool/SMB pre-assembled. If you only need one breath, then basically there is no change in buoyancy. In the worst case you’ll be a tiny bit negative if you do a full exhale and are slow to get back on the reg.

Slightly raising your left shoulder should be enough to vent any excess buoyancy. Also if you do get dragged up by a bag, just let go. For some reason people often grab hold for dear life . Embarrassing but we've all bolloxed up a blob shoot before. Just suck up the shame and hope the skipper picks it up topside.

This ... besides, in case you lose the (inflated) bag, it usually isnt a big deal, as after a few seconds the spool will come back down. Just be ready to catch it. And in case you miss this too, take the line in a loop, attach a double ender to it, and drop it on the non-spool side. This will bring the spool back up. Like so:

 

[CptTightPants21]

You should have been neutrally buoyant when you started deploying the bag. You were so close to netural that adjustment should be made with your lungs (primary) and slight kicking (secondary). When you started this drill you were neutral, dumping gas will typically be too much gas release and can cause your depth to seesaw as you are now too negative. If dumping gas is really needed, there are other factors at play such as you weren't neutral at the start of the drill or you are so task loaded you are subconsciously holding excess air in your lungs. If you need to dump gas before you have inflated the bag, you weren't neutral at the start.

There is no set way to prepare the bag, although you will see most videos with the spool in the left hand prior to being released. In all the training I have done (8-9 instructors) I have never grabbed the primary reg with my left hand so the movement and feeling would be alien to me. As Graeme Fraser noted, slightly raising the left shoulder or switching the reel/spool from your left hand to right hand in order to dump is easy enough. I don't want to make it sound like I am saying 'never dump, never dump', but the need to dump while shooting a bag is more a technique and fundamental skill issue. When just starting out, focus on your breathing and slight kicks to get used to the buoyancy and shooting a bag, don't go into it with the mindset of dumping gas to maintain depth

 

[BlueTrin]

You should have been neutrally buoyant when you started deploying the bag. You were so close to netural that adjustment should be made with your lungs (primary) and slight kicking (secondary). When you started this drill you were neutral, dumping gas will typically be too much gas release and can cause your depth to seesaw as you are now too negative. If dumping gas is really needed, there are other factors at play such as you weren't neutral at the start of the drill or you are so task loaded you are subconsciously holding excess air in your lungs. If you need to dump gas before you have inflated the bag, you weren't neutral at the start.

There is no set way to prepare the bag, although you will see most videos with the spool in the left hand prior to being released. In all the training I have done (8-9 instructors) I have never grabbed the primary reg with my left hand so the movement and feeling would be alien to me. As Graeme Fraser noted, slightly raising the left shoulder or switching the reel/spool from your left hand to right hand in order to dump is easy enough. I don't want to make it sound like I am saying 'never dump, never dump', but the need to dump while shooting a bag is more a technique and fundamental skill issue. When just starting out, focus on your breathing and slight kicks to get used to the buoyancy and shooting a bag, don't go into it with the mindset of dumping gas to maintain depth

I agree with you but I use a very large DSMB which has no mouth inflator adapter, I need to use my alternate to inflate it. This is why I won’t be neutral after inflating it. I try to start neutral with my lungs a bit more inflated, then I keep my lungs more empty when inflating it.

I don’t plan to dump, just want to be able to do it if I need it.

I don’t have a lot of experience in drysuit (or even not much experience diving in general) I’ll practice the shoulder thing.

 

[1atm]

One more thought: all the replies above assume you are using a closed, oral inflate SMB (which is what I would recommend). In case you use an open bottom SMB that is filled by purging the octopus into it, then of course you will become more positively buoyant during the process. I am no expert in that kind of SMB (I chose the oral inflate type instead), but if I had to guess the following would help:
- Good horizontal trim, fins flat (= more inertia and more time before you move up)
- Slight upward kicks (assumes neutral trim, or slightly head down trim)
- Timing your exhale in sync with the purge
- ...

Some divers I have observed, are slightly negative and use fin kicks to maintain depth, but I dont think thats a good habit to get into, regardless of SMB type.

But maybe someone who uses this type of SMB regularly can give better advice..

Edit: typos ...

 

[1atm]

Also remember that you dont need to fill the bag completely, the gas will expand as the SMB ascends.