Safety sausage vs DSMB

[outofofficebrb]

What happens to the sealed ones at the surface if they are under inflated? Do they flop over too?

If they are under-inflated, you can pull the line taut and it will make it stand up. The air is stuck in it until you release the OPV. It's better if you have a longer one so more remains visible above the water if that happens. I have no qualms about filling it full because of the OPV. If it's too much, it'll let out. Not enough, and, well, it is what it is. When I had the self-sealing one, if it flopped over, sometimes the air would escape as it's not always a 100% seal. The opening over wear and tear, especially. Even if pulling the line taut, if that happens, it would become flaccid. Also, when I shopped for the self-sealing, it was difficult to find a self-sealing with an OPV that was narrow so it always took a lot more air to fill it. When purging a second stage at a safety stop it required more careful planning because of the amount of lift that comes with it immediately upon deployment. I actually found it challenging when I was first learning to deploy at depth so I recommend a skinnier, narrower one for that reason. I like the skinnier/narrower ones (like Halcyon's 3.3ft/1m or 6ft one) because it doesn't take many puffs of air from the mouth to do an oral inflate and the lift isn't so great which is helpful when there is a lot of moving and shaking in the water column. You can even use your LP hose.

 

[rsingler]

What happens to the sealed ones at the surface if they are under inflated? Do they flop over too?

Yes.

This whole discussion really revolves around having the right tool for the job.
If you just need a signaling device for the surface, a 72" narrow (4") weenie is best. It won't take lots of effort to fill properly, and pulling the bottom just below the surface at even suboptimal fills will make it stand straight up.
The notion of using a DSMB, which is maybe 6" in diameter is using the wrong tool for this job. The sealed ones may take a lot of filling by mouth, though yes, using an LPI hose (with the appropriate DSMB) will fill easily. But then holding the bottom end below the surface when it's so big is a new effort.
As noted above, the semi-closed do not inflate and stabilize as easily at the surface. Yes, you can make it work. Yes, everything everyone's said is true. But for $24, get the easy signaling device until you NEED a DSMB. Many weenies with a loop, carabiner or bolt snap at the bottom can be used as a DSMB if that's what's asked of you.
You only need a 72" x 6" monster if you need it. And that's deploying at depth, hanging off at a deco stop or 15' and/or drifting downcurrent from your boat.

I'm just not sure that we're giving the best advice to the OP at his current dive count, when we start down the usual SB path of DSMB, BP/W, DIY reg service and Solo Diver.
@Wookie was right. So was everybody else, maybe. But for THIS diver? I still vote for a sausage. Deploy it from depth the next time it's "required" on his drift dive. And when he gets to the surface, see how many 6" pylons are there, compared with 4" as the boat makes its pickup rounds.

My 2 c.

 

[lermontov]

Yes.
I'm just not sure that we're giving the best advice to the OP at his current dive count,

the way i read it is divers are giving advice based on their own journey - ie buy a device that will still be useful as your dive experience grows rather than getting one now and other/different one later. thats the advice i appreciated as i started down the dive path.
But really - its not that hard to shoot an smb and I certainly wouldn't do a 'course' look on u tube
my 2c worth- if you can hold your position in a column of water your ready to shoot an smb- go buy one and practice -