DSMB importance

[boriss]

Dive flexible skill for open water dives 1-4.
Inflatable Signal Tube Use — Deploy an inflatable signal tube at the surface, or deploy a delayed surface marker buoy (DSMB) from underwater.
There are enough instructors choosing surface deployment that there is a PADI specialty specifically for dSMB deployment. I like to practice it if I’m not ascending up a mooring line.

Ohhh... I see what you mean now. Deployment portion is optional. I'm with ya

 

[FF / EMT]

All signals really need to pre-agreed. But the standard simple signals are

Orange/Red DSMB = All Good
Yellow = Problem (needs investigation) {1}
Red + Yellow (2 SMB's) = Out of gas issue - Deploy drop cylinder/safety divers. {2}

{1} My yellow DSMB has laminated standard messages that can be torn off leaving the most appropriate.
{2} if you are using drop cylinders they need to be pre-rigged, and the boat needs to aware of the action to take. This is all part of the initial dive planning and briefing.

If we see a Yellow + Red we would put divers back in to determine the issue and offer support/gas.

Stupid question, and please forgive me, but how or why are you going to launch 2 dsmbs for an OOA.
One, what is anyone on the surface going to do,
Two, it’s a waste of time, and air.

 

[rongoodman]

is a requirement just like a snorkel.

In what universe would that be?

 

[rongoodman]

Stupid question, and please forgive me, but how or why are you going to launch 2 dsmbs for an OOA.
One, what is anyone on the surface going to do,
Two, it’s a waste of time, and air.

More likely to be an out of gas issue involving extended deco, where the divers couldn't simply go to the surface without risking serious injury. Surface support would have been established prior to the dive and spare gas would be ready to go. Unlike recreational dives, a defining feature of technical dives is that you no longer have direct access to the surface in case of a problem.

 

[Gareth J]

Stupid question, and please forgive me, but how or why are you going to launch 2 dsmbs for an OOA.
One, what is anyone on the surface going to do,
Two, it’s a waste of time, and air.

You should know you have an air issue before it becomes catastrophic.
For OC dives
- you have had a significant overrun (perhaps due to being trapped in wreck).
- you have a free flow, so shut down the effected cylinder, but have lost sufficient gas to compromise the ascent / decompression.
- you are assisting a buddy
- you have lost decompression gas at the switch.

For CCR dives
You may have had a unit failure. On longer, deeper dives, the decompression phase may require additional gas to be dropped from the surface. Even when using team bailout, it is safer to get additional gas from the surface.

On more complex dives, if it suits, we would have a trapeze in the water with additional gas clipped of on the bottom bar.

I predominantly use combination DSMB's that have the option to use a CO2 cartridge. I also carry a traditional AP DSMB. On CCR, I tend to deploy using the CO2 cartridge, it's a lot easier. On the occasions I have screwed up and not replaced the cartridge (or the striking pin snaps - a point to be aware of), then I can fill them in the traditional manor, via the nozzle.

 

[Searcaigh]

In what universe would that be?

Australia, it's mandatory down unda'

 

[boriss]

In what universe would that be?

PADI OW Universe

 

[FF / EMT]

You should know you have an air issue before it becomes catastrophic.
For OC dives
- you have had a significant overrun (perhaps due to being trapped in wreck).
- you have a free flow, so shut down the effected cylinder, but have lost sufficient gas to compromise the ascent / decompression.
- you are assisting a buddy
- you have lost decompression gas at the switch.

For CCR dives
You may have had a unit failure. On longer, deeper dives, the decompression phase may require additional gas to be dropped from the surface. Even when using team bailout, it is safer to get additional gas from the surface.

On more complex dives, if it suits, we would have a trapeze in the water with additional gas clipped of on the bottom bar.

I predominantly use combination DSMB's that have the option to use a CO2 cartridge. I also carry a traditional AP DSMB. On CCR, I tend to deploy using the CO2 cartridge, it's a lot easier. On the occasions I have screwed up and not replaced the cartridge (or the striking pin snaps - a point to be aware of), then I can fill them in the traditional manor, via the nozzle.

You said drop your cylinder, as if it was a single tank recreational Dive.

 

[RIHappyDiver]

PADI OW Universe

Required during training, highly recommended by PADI afterwards, but your choice. PADI will not take your certificate away if they find out you are not using a snorkel.

Erik

 

[Stoo]

DSMBs are not important at all. Until they are. Then they're really important.​

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Depending on where and how you're diving, they can also be a matter of courtesy. The Missus and I never stay with a group we're diving with (with the Captain's blessing.) As a matter of courtesy, we blow a sausage after every dive. It saves him having to wonder where we are while he's dealing with other people. One look, he sees us, and he's happy.​

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