DSMB is flaccid upon deployment. Looking for tips.

[Tigerpaw]

THANKS to everyone for your responses, especially the comedic ones, they made me laugh and I needed that laugh because I was getting frustrated and upset.
I was practicing at the top of a platform which is at 20ft. Later this week, I'm going to go to 40ft and use the formula Inquis quoted. Then I'll try it again at 20ft.
Afterwards I'll come back and let you all know how it went!

 

[steinbil]

How big is it?

In all seriousness, if it's too big, it's gonna take several breaths to get it hard...err I mean full, which is complicated. I use a 3.3' SMB for oral inflation. A bigger SMB for open ocean I would inflate with my drysuit hose. Being shallow and having a long SMB not only requires more breaths, it also exaggerates the difference in ambient pressure between you and the SMB, remember that when calculating how full the SMB has to be. If you're at 20ft, the air bubble in a 6ft SMB is at 14-17ft, meaning you need more than you think.

 

[BlueTrin]

You can use your drysuit hose as @steinbil said.

You could try to check how many breaths you need to inflate it at the surface and back out how many breaths you need at 10, 20, 30,40 meters to inflate it?

 

[Wibble]

The best answer -- which is extremely common in UK diving -- is to use a self-inflating SMB. These can use either a mini cylinder (0.1 litre) aka a Crack Bottle, or use a CO2 cartridge for inflation.

These are extremely simple to deploy from any depth and result in a nice stiff SMB on the surface.

Who makes SMB's with small air cylinders?

Besides the AP Diving SMB with inflation cylinder AP Self-sealing SMB Marker Buoy with Inflation Cylinder - does anyone else know of any manufacturers of similar DSMB's with inflation cylinder?

scubaboard.com

 

[BlueTrin]

The best answer -- which is extremely common in UK diving -- is to use a self-inflating SMB. These can use either a mini cylinder (0.1 litre) aka a Crack Bottle, or use a CO2 cartridge for inflation.

These are extremely simple to deploy from any depth and result in a nice stiff SMB on the surface.

Who makes SMB's with small air cylinders?

Besides the AP Diving SMB with inflation cylinder AP Self-sealing SMB Marker Buoy with Inflation Cylinder - does anyone else know of any manufacturers of similar DSMB's with inflation cylinder?

scubaboard.com

I’d use a cartridge myself if I had to choose (I don’t have one). I think cylinder has to be closed before to let go, or you risk water ingress. (Even though AP can service them as @Wibble said)

 

[BoundForElsewhere]

The best answer -- which is extremely common in UK diving -- is to use a self-inflating SMB. These can use either a mini cylinder (0.1 litre) aka a Crack Bottle, or use a CO2 cartridge for inflation.

These are extremely simple to deploy from any depth and result in a nice stiff SMB on the surface.

Who makes SMB's with small air cylinders?

Besides the AP Diving SMB with inflation cylinder AP Self-sealing SMB Marker Buoy with Inflation Cylinder - does anyone else know of any manufacturers of similar DSMB's with inflation cylinder?

scubaboard.com

How do you get those CO2 cartridges on an airplane?

 

[Superlyte27]

Use a bolt snap! Lol

Let out about 6-10’ of line and clip a bolt snap to the line. The bolt snap drops below you, keeping the line tight. There’s no excess line to get tangled in, because it’s all tight below you. Now, without worry about getting tangled, with reel in one hand, inflator in the other, inflate SMB hard as you can. It’ll start shooting up pulling the 10’ of line up with it, instead of you. When the bolt snap gets to the reel, remove the bolt snap.

 

[Wibble]

How do you get those CO2 cartridges on an airplane?

Buy them when you get there? Just standard 16 gram cartridges for cycle pumps, whipped cream, etc.

If flying, I would make sure I add the drysuit inflate hose and duct/Gaffa tape it to the SPG hose (or put a bolt snap on the drysuit inflate and clip it to the LH hip D-ring where the SPG would go. Or if using a jacket BCD, clip the drysuit inflate hose to the LH chest D-ring.

I’d use a cartridge myself if I had to choose (I don’t have one). I think cylinder has to be closed before to let go, or you risk water ingress. (Even though AP can service them as @Wibble said)

I believe the crack-bottle (mini-cylinder) valve can be partially opened so that:

• It inflates more slowly making it easier to sort out any crap before the bag flies upwards
• Some gas is left in the cylinder so water doesn't get in

Personally I prefer the CO2 cartridges as they're very simple, smaller than the crack bottle and doesn't require you to find an open circuit diver to donate their cylinder to fill your crack-bottle from their gas

 

[BlueTrin]

Buy them when you get there? Just standard 16 gram cartridges for cycle pumps, whipped cream, etc.

If flying, I would make sure I add the drysuit inflate hose and duct/Gaffa tape it to the SPG hose (or put a bolt snap on the drysuit inflate and clip it to the LH hip D-ring where the SPG would go. Or if using a jacket BCD, clip the drysuit inflate hose to the LH chest D-ring.



I believe the crack-bottle (mini-cylinder) valve can be partially opened so that:

• It inflates more slowly making it easier to sort out any crap before the bag flies upwards
• Some gas is left in the cylinder so water doesn't get in

Personally I prefer the CO2 cartridges as they're very simple, smaller than the crack bottle and doesn't require you to find an open circuit diver to donate their cylinder to fill your crack-bottle from their gas

Or you can terrorise people on the boat with these cylinders and whip. Other divers won’t know if you serviced it when you charge them

 

[TrimixToo]

The deeper you are, the easier it is to shoot a bag of any kind. The volumetric expansion that occurs as the bag rises means less volume is needed when you're deeper. At 33 FSW you need have the bag (edit) *half* full for it to be completely full at the surface, but that represents half the buoancy of the bag (say, 50 lbs for a 100 lbs bag). At 99 FSW, you only need a quarter of it. And so on. The hardest place to shoot a bag from (and have it full or nearly full at the surface) is a shallow spot, not because it's hard to fill the bag, but because it's hard to stay neutral while you do it without plummeting when you finally release the bag.

THANKS to everyone for your responses, especially the comedic ones, they made me laugh and I needed that laugh because I was getting frustrated and upset.
I was practicing at the top of a platform which is at 20ft. Later this week, I'm going to go to 40ft and use the formula Inquis quoted. Then I'll try it again at 20ft.
Afterwards I'll come back and let you all know how it went!

(Edit) This is also why buoyancy control is easier the deeper you go. Practice it shallow (like at 10'). *Anybody* can keep buoyancy perfect at 200'; it's dead easy. Well, anyone with the right certs and gas, anyway. It's viciously hard to keep your level perfect at 5'.