Inflating dsmb without flying up with it

[Brett Hatch]

Brett and I were posting at the same time. One note on the video. Save yourself a few steps and have the spool already rigged up to the DSMB before you splash. Keeping them separate is for divers who carry multiple spools/reels/DSMBs for whatever reason (such as running lines when wreck diving).

That's a good point, I prefer to pre-rig the DSMB/spool as well. No sense futzing about with it mid-water since I don't use a reel for anything besides DSMB launch.

 

[NothingClever]

The dude who swims past at a 45 degree angle made my head crazy.

I think to put the crowning touch on matters he should have used the bicycle kick.

 

[johndiver999]

This may not be the right forum to ask but would like to know how you can properly inflate your dsmb fully without being towed to the surface when it's only half full.

DUMB IS DSMB AFTER SPELL CHECKER GETS DONE WITH IT LOL. (Mod edit, fixed your title for you)

It depends... It depends on your depth and the size of the smb. If you are deep and the smb is small, then only a little bit of air is required in order to allow gas expansion to provide full inflation at the surface.

Conversely, if you are shallow (like 20 feet) and you have a huge smb, there is absolutely no way to remain neutral and place enough volume in the marker to ensure it will be fully inflated on the surface.

If you are on a "safe" bottom, and you have had a lot of wetsuit compression, you can dump all the air from your BC and make yourself as heavy as possible (and kneel - while begging forgiveness from the scubaboard activists) and then keep adding air to the smb until it starts to pull you up and then immediately let go of it. If you screw that little activity up, you can be going for a ride to the surface.. and suffer whatever consequences occur. Not something I would recommend.

It is safer to be deeper, and add only a little bit of air in the smb, so that if you release it and you get tangled in it, you can exhale and just pull the thing back down a few feet, dump the air and then try to remedy the situation and you get a free do over.

Lastly, it is often NOT necessary for an SMB to be fully inflated at the surface for it to serve its intended function. If it is 2/3 full and you keep some downward tension on it, then it should stand up and be reasonably visible.

 

[lermontov]

This may not be the right forum to ask but would like to know how you can properly inflate your dsmb fully without being towed to the surface when it's only half full.

DUMB IS DSMB AFTER SPELL CHECKER GETS DONE WITH IT LOL. (Mod edit, fixed your title for you)

hi bob the deeper you are to launch it the less air you need to start it on its way to get ti adequately inflated on the surface, so the less likely it will catch you out. I prefer a spool that has a large diameter so that my fingers dont get jammed in it as it starts to unwind i also use my dry suit hose - i just find it easier.
On another note practice getting the smb ready to launch before your depth or 'spot' it shouldn't take more than 15 seconds once you in position. the video is a demo only but dont faff around for 3 minutes

 

[Jafo19D]

Here's a decent video of a diver demonstrating how to do it. The first 2 minutes of the video they are doing something else, so skip to 2:15 mark or so.

Notice that the diver completely prepares the DSMB before blowing it up. It is unravelled, and both the buoy and the reel are in their left hand. That leaves their right hand free to handle the reg in their mouth. So they remove the reg, blow a breath into the buoy, and replace the reg. At this point, they will still be neutrally buoyant, because the gas in the buoy was a moment ago in their lungs. They will only become buoyant if they take in a big breath, but can stay neutral by taking small breaths at the "bottom" of their lungs, ie not fully inflating their lungs.

Once they do this, the buoy is halfway filled. Notice that at this point the DSMB is not attached to their body, it is loose in their hand. They do a quick check above to make sure they buoy won't become entangled on kelp or a boat or another diver or whatever. They move the DSMB and reel away from their body which will keep themselves from being entangled. And finally release some grip on the reel to allow the buoy to shoot upward. As the buoy goes up, the gas inside will expand such that it is fully inflated when it arrives at the surface (this is why DSMBs have an overinflation valve).

At that point, they can clip the line off to the reel with the double-ender, which will allow the diver to let go of the buoy and reel -- it's not going anywhere.

Some folks prefer to fill it from a drysuit or inflator hose. I guess the upside there is that they don't have to remove their reg from their mouth. The downside is that they are not transferring gas from one low-pressure compartment (lungs) to another low-pressure compartment (buoy). Instead it's from the high-pressure compartment (tank) to the low-pressure buoy. So it causes a net increase in buoyancy, versus from the lungs causes no net change in buoyancy, and makes the whole thing more time-sensitive since you'll have to swim down until the thing is deployed, which makes it harder to deploy than it would be if they could relax.

What you say makes perfect sense but when I tried this a couple of weeks ago the DM freaked out that I was taking the reg out of my mouth.

 

[lermontov]

What you say makes perfect sense but when I tried this a couple of weeks ago the DM freaked out that I was taking the reg out of my mouth.

you could use the other one

 

[Akimbo]

Plenty of how-to advice above. Wrap your legs around the anchor chain and practice until you have mastered it, if you're diving off a boat. If nothing else, it will take the worry of emulating a Trident missile off your mind so you can concentrate on learning the technique. That's what I did.

 

[Brett Hatch]

What you say makes perfect sense but when I tried this a couple of weeks ago the DM freaked out that I was taking the reg out of my mouth.

Maybe your DM needs to take a chill pill

In seriousness though, not everyone teaches to orally inflate. Inflation from a LP hose works. Inflation from the alternate second stage (for open-bottom DSMBs) also works. There are also special DSMBs which take a single-use cartridge to inflate themselves, which work. Each approach has trade-offs.

Oral inflation is my favorite one since *to me* it seems least likely to mess up my buoyancy, and least likely to cause me to be entangled, both of which are safety concerns. I don't mind taking my reg out of my mouth for a few seconds to blow the sucker up (I should hope not, since I dive a primary-donate / secondary-necklaced reg config!). For other folks, the tradeoffs line up differently for them, which is fine, more power to 'em.

 

[ChuckP]

This too - your smb does not need to be fully inflated at the surface, yes the more the better BUT no point in fighting a simple procedure. If you have a six foot huge smb and you put a decent breath in it at 60', it'll be pretty full - if you're doing it at 20', well, what do you expect?

If the thing is half full, and you really must have it standing up, just hang on your reel/spool at SS, your negative weight will stand it up, it doesn't take much.

The reg out of your mouth method leaves you perfectly neutral and completely in control.

 

[NothingClever]

Sounds like a weak DM that needs remediation.

Taking the reg out of one’s mouth is a Basic OW skill that remains useful long after the course whether at 15m or 50m.