Smb

[MrMojo]

Hi all i was doing some training with a smb, as alot of dive boats and Dm's do not let you on a boat in the uk unless you are trainned or have a smb with you which is good .I was wondering what your prefered method of inflating an smb was as there is is so many different methods.Is it main reg.octo.exhast bubbles , bcd valve or inflator valve/gun.i would even like to hear the dir point of view as this seems to be a serious task loading procedure at depth with the chance of things going wrong and ending in tears.
All and any advice welcome

Regards ,

MAL...

 

[Genesis]

then inflate it with my primary reg.

But I dive a long hose on my primary.

When I used to dive a "traditional" setup I inflated it with the octo, but I found that this could be a rather dicey situation depending on what you were doing. If just shooting the bag, no big deal. But if you were doing it to lift something, then the hose length on a regular octo was often not long enough to truly be comfortable in inflating it while ensuring you didn't have interference between you, your kit, and what you were lifting.

I don't have a closed-circuit bag that requires the use of BC (or drysuit) inflator hose.

 

[Uncle Pug]

I have two... both closed... inflate with drysuit lp hose.

You are right MAL... something that should be practiced because it does have the potential to ruin your day.

We dive in teams... and the guy who is shooting the bag takes care of that and managing the spool. The other guy is responsible for calling and timing the stops.

When the bag man is ready to inflate he makes sure that neither the bag nor the line will foul on him.... he inflates and gets the OK from his buddy before releasing the bag. The spool is left to spin free in the water and when it stops the bag man secures it with the double ended bolt snap.

watch this

 

[JT2]

Thanks for the clip Pug, that was cool.

 

[boomx5]

http://www.gue.com/equipment/feature/liftbag/index.shtml
It's got some good footage to.

 

[madmole]

Must be nice to dive in a place where a 10 Kg bag and cotton real would work as a DSMB

Here in the North sea and English channel 25-50 KG sausages 6'- 12 ft long are the norm with 80-100m of thick line and a 4-8" reel. You certainly cant inflate one of them and continue to hold it

BSAC include DSMB deployment in the basic diver grades as its a compulsory skill here

 

[roakey]

madmole once bubbled...
Must be nice to dive in a place where a 10 Kg bag and cotton real would work as a DSMB

Here in the North sea and English channel 25-50 KG sausages 6'- 12 ft long are the norm with 80-100m of thick line and a 4-8" reel. You certainly cant inflate one of them and continue to hold it

That's an 80 pound bag, so about 36kg, right in your "zone." It's not cotton, it's at least #24 braided nylon line which is 250 pound test.

As for 80m of line on a reel, are you sending up bags from that deep? And if you are, sure you can hold the bag, since the gas volume is going to increase by more than 7 times on the way up!

Sounds you're doing one of two things wrong. Either you're carrying way too much line because you're sending up bags from a fairly shallow depth, or you're putting way too much gas in the SMB if you are in fact sending them up from a fairly deep depth.

Roak

 

[madmole]

We need the long suasage shape to stay upright to be visible in the swell, the short round lift bag types are not visible in UK Waves, to stay upright it needs to be full and you need to keep tension on the line or it flops over. The line also needs to be able to have extra deco tanks sent down it and message buoys sent up hence the thicker line (hopefully only if there is a problem)

1/9th (80m) of a 2m long 25cm sausage contains 1.7 litres of gas, like to bet you can hold that!!!!, certainly not on a rebreather as you cant breath out to compensate. and it gets worse as you get shallower

200/9 = 22.2
2 pie 12.5 = 79
79 x 22.2 = 1720 cc or 1.7 litres
Rough back of envelope calcs

(edited cos I cant do maths properly!!!! and I measured my blob)

At 40 m thats 3.4 litres needed.

I have reels with 50, 80 and 125m of line, I take the most appropriate

I just fill until I feel myself start to move and then let go. Normal prceedure here in the cold murk is for your buddy to clip his reel to yours, that way if yours jams (and fortunately in hasn't in the last 1000 or so times I've sent one up) you let go and you carry on sending the blob up on his reel. Or tie your reel to the wreck first so you can hold the bouy

The strong currents here mean we always deco on our blob lines hence the need for stronger line. Standard proceedure is to send a second yellow blob up the same line if we have a problem, the main blob is red. Second blob always results in extra gas coming down asap