Launching a DSMB

[Dan]

A problem can occur when in low vis or in current and relocating the anchor / shot line for ascent is not possible.

I much prefer deploying the DSMB prior to surfacing in order that the boat crew know where I'm drifting off to as I'd hate to find myself 100m away from a small boat in choppy weather and hope that somebody spots me as soon as I inflate the sausage.

We were warned to not wandering too far from the anchor line. They also put another guide line along the bottom to good sites to see. The current is pretty much nil at / near the bottom with fantastic visibility > 80’ in six times I’ve been diving there since 2005. I have yet heard anyone get blown away & lost at sea from this boat operation.

 

[Searcaigh]

Most of my local diving is in poor visibility so perhaps my expectations are a lot lower

I would like to see more OW divers use DSMBs though in our locale, and I personally carry a second reel and DSMB in the tail pocket of my wing.

I do remember having one that folded into a built in pocket with something like 6m of string about 20+ yrs ago and it was a while before I bought another with a reel.

Thankfully the design has improved over the years and all of mine have a dump valve as well as manual inflation that can also be inflated using an LP hose. I don't remove my drysuit inflater hose when I move to wetsuit diving as it has this secondary use.

 

[Billy Northrup]

Awesome, real world seldom looks like a demonstration.

 

[Sbiriguda]

Thanks for this informative thread...
I bought a DSMB buoy like this one:
Cressi Buoy Deco Pro comprare e offerta su Scubastore
And a 30 meters spool:
Seacsub Spool Reel comprare e offerta su Scubastore

By now I would like to cut the spool line and use only 15 meters

As far as I understand, to inflate the buoy there are the following methods:

1) Mouth inflation (in DSMB of the type I bought)
2) BCD hose (like in the video)
3) Secondary regulator
4) Primary regulator without removing it from the mouth,
that is releasing some air to make the buoy more or less neutrally buoyant and adding even more air to shoot the buoy to the surface, always without taking the reg out of the mouth
5) CO2 cartridge inflation
6) Refillable 'crack' bottle inflation

EDIT
Added the 2 other methods

Which is the best way for you? Do you have any safety suggestions, especially in order to avoid being pulled up by the DSMB when it's already inflated?

 

[Topper133]

Add 2 more methods.

5. CO2 cartridge inflation
6. Refillable 'crack' bottle inflation.

Best way for me all depends on where and what I am diving. 1,3 & 4 are of no use when on CCR for example (well maybe some use 1 but I don't remove the loop unless necessary).

 

[Topper133]

Do you have any safety suggestions, especially in order to avoid being pulled up by the DSMB when it's already inflated?

• Do all your work holding it out in front of you while in trim, not under you looking down on it.
• Don't stick your finger in a spool. Finger and thumb held each side.
• Slightly inflate the DSMB, only slightly, this lets it rise and keeps it clear of you, it will add very little to no buoyancy, then you can check above you, check your line\reel\spool, then fill it enough as required. (not always possible with certain methods, i.e. CO2 cartridge)
• During ascent, keep the line taut, but don't pull yourself up it, it's not there to compensate poor buoyancy.
• If it jams, let go!

 

[Lobzilla]

• Do all your work holding it out in front of you while in trim, not under you looking down on it.
• Don't stick your finger in a spool. Finger and thumb held each side.
• Slightly inflate the DSMB, only slightly, this lets it rise and keeps it clear of you, it will add very little to no buoyancy, then you can check above you, check your line\reel\spool, then fill it enough as required. (not always possible with certain methods, i.e. CO2 cartridge)
• During ascent, keep the line taut, but don't pull yourself up it, it's not there to compensate poor buoyancy.
• If it jams, let go!

Good suggestions, especially the first one.
When diving in flat trim our work space is in front of us and not under our chest. Took me a while to get this in my head.

If the SMB is launched from 30 feet (~2ATA) then half full is enough. At 60 feet (~3ATA) 1/3 full and so on.

Coincidentally, I found this and that yesterday. IMO it is better to overthink a procedure a little bit on land rather than have an overlooked detail turn it into a mess in the water.

 

[DanielRJones]

Carry 2 on every dive have a sealed dsmb with oral/ lp hose attacjed to my reel and clipped off on my back and also have a co2/oral inflate in my drysuit pocket with my spare spool and 2 spare co2 canisters.

I am launching off the bottom unless i am coming up a line when i will pop it at 5m

 

[Sbiriguda]

I am curious about co2 cartridges never used one. Do they fit only in specific DSMB or can they be used in any, maybe with an adaptor? Can you post a link to co2 cartridges for scuba DSMB? Can you use other types of cartridges for example the ones for bycicle tyres?

 

[Topper133]

1m CO2 SMB (Single CO2)

They are specific SMBs, the cartridges are single use so need replacing after every use. Box of 12gm CO2 Cartridges (10/30/50/100)

They're handy, but I don't use one, in the UK I use a large reel and an AP crack bottle with 1.4m DSMB.