SMB size vs. ease of shooting from depth for a newb

[FuzzyNutz]

After reading a lot of the posts here, I'm deciding to go with a Halcyon smb as my first smb. Now I'm stuck on what size to get. My instinct tells me to get the 6 footer because, well, a big one in calm seas is not a problem, and a small one in rough seas is a problem. I've never shot an smb before, so I don't really know what to expect when I do it or how much size matters in these regards, but I'm guessing there is a significant change in deployment.

Given that I've never done it before, would I be at a high risk starting off with a 6' smb? I'd definately practice this drill over and over in a pool before I ever put it to practical use, but I also don't want to put myself at an unnecessary high risk.

Is it possible to orally deploy a large smb safely (from 15' safety stop depth), or is it generally best to use your inflator hose? I guess I'm worried that I'll start ascending to the surface after a few breaths without getting the smb fully inflated (well, inflated enough to become full when it reaches the surface to stand upright). I know I'll figure all of this out soon enough when I get some practice in, but I'm just looking for a little heads up.

Also, could someone clarify if the Halcyon SMB has a clip at the top to attach a light-stick/strobe for use during the night?

 

[limeyx]

It's a tough call. I think most people start with the 3 footer. This can easily be orally inflated at depth (1 breath usually does it) and even at 20 feet would only take maybe 2-3 breaths.

However, as you point out, in rough seas, they can be hard to see. I have had 2 cases locally where the 3 footer was either very hard or impossible to see.

the 3 footer is much easier to manage, and unless you are going to be diving in rough oceans, probably best to start there.

The 6-footer you are probably going to find you need to inflate with a hose, so then you either need a spare hose somewhere, or have to detach a wing or drysuit connector (not ideal)

Generally I take the 3 foot bag unless I am diving in a high boat area (Shipping lane) or if I know the seas will be high.

 

[FuzzyNutz]

Yeah, that's where I'm stuck. And I thought it may be best to just get 2 sizes, but then I figured larger may be better even in calm seas if I happen to drift pretty far away.

If I may ask, why is it not ideal/what are the potential risks of disconnecting your hose? (I think it's not ideal also, but I really have no logic behind it). I assume I would fully deflate my wing (there's usually no air in there anyway - at least on my carribean dives), disconnect my hose, send the bag up, then fiddle with my hose and wing again after the bag has reached the surface. Now that I think about it, if a problem with buoyancy were to arise while shooting the bag, I most likely wouldn't be wanting to add air to my bc. Hmmm...

 

[azchipka]

I carry a orange 6' as a primary and a yellow 3.3' as an emergency signal. Short write up here Here

Post is more designed for my students but could be helpful

 

[rjack321]

Is it possible to orally deploy a large smb safely (from 15' safety stop depth), or is it generally best to use your inflator hose? I guess I'm worried that I'll start ascending to the surface after a few breaths without getting the smb fully inflated (well, inflated enough to become full when it reaches the surface to stand upright). I know I'll figure all of this out soon enough when I get some practice in, but I'm just looking for a little heads up.

Forget it. The 6ft SMB has about 55lbs of lift (surface). The ONLY way you can get it full is to shoot it deep, probably deeper than your dives, like 100+fsw. And you need to use a hose to inflate it. Of course its only a "big" SMB if its full too. If you shoot it shallow and its only 20% full it might as well be a small SMB.

Its better to get a small ~3ft, 5-8lbs lift SMB and learn how to use it properly (from a buddy, mentor or instructor). Then once you have the mechanics down consider larger SMBs if/when the dive requires them.

 

[limeyx]

Yeah, that's where I'm stuck. And I thought it may be best to just get 2 sizes, but then I figured larger may be better even in calm seas if I happen to drift pretty far away.

If I may ask, why is it not ideal/what are the potential risks of disconnecting your hose? (I think it's not ideal also, but I really have no logic behind it). I assume I would fully deflate my wing (there's usually no air in there anyway - at least on my carribean dives), disconnect my hose, send the bag up, then fiddle with my hose and wing again after the bag has reached the surface. Now that I think about it, if a problem with buoyancy were to arise while shooting the bag, I most likely wouldn't be wanting to add air to my bc. Hmmm...

The best way to learn to shoot an SMB is to take an in-water class honestly.

I would not deflate my wing, because if there is some gas in there, then as soon as you send the bag up, you will be negative afterward...and then if you have disconnected your wing/drysuit hose, you may have a buoyancy issue (which is why a spare hose is a good idea)

I would honestly start with the 3 footer, get a mentor to help you out with rigging and shooting it, or take a class that covers that skill.

Once you've got that down, then maybe try to borrow a bigger SMB and see how that goes.

 

[FuzzyNutz]

I think I'll take the advice to start with the 3 foot bag. My priority right now is to have one for my upcomming Cozumel trip, and a small bag should be perfectly fine there - and the more I dive, the more nervous I am about not having one. It'll be the ScubaBoard Invasion, so I'm thinking someone will be kind enough to 'show me the ropes' while on a safety stop - either that or I can tip the DM a little more to show me. I guess if the size issue really gets to me, I could always get a large safety sausage to stow on my backplate for if something were to go really wrong on the surface. I'd really just like to use the oppurtunity of this trip to learn to shoot a bag from depth. Thanks for all the great replies so far!!

 

[watboy]

I carry 2 SMB's, the small 3 foot one in my thigh pocket, and a big 6 foot one tucked in my BPW. As most of my diving is tropical reef diving, I generally shoot the small one from my safety stop. My primary concern is not to get hit by the small boat traffic. The 6foot one is there for if I need it to signal on the surface. If I'm drift diving, I'll launch the 6 foot one when i'm at 10 meters. I inflate it with my octopus, it took some practice but i can get it fully inflated from 10 meters. You should use a spool and as others have commented, its probably best to practice using the spool with the 3 foot one. But you can always carry the 6 foot one to deploy once you are on the surface. I did try the narrow 6 foot ones, thinking it would be bigger and easier to launch. But I found that when wet, they flop over.

 

[Tortuga68]

I did try the narrow 6 foot ones, thinking it would be bigger and easier to launch. But I found that when wet, they flop over.

You need more tension on the line ie be (more) negative. Of course this means your 6' SMB is now only a 4-5' SMB, as that's all that's above the waterline. So if you're in high seas or far from the boat (the reason for having a big SMB in the first place) then you're not getting the full benefit you were looking for in the first place

 

[watboy]

You need more tension on the line ie be (more) negative. Of course this means your 6' SMB is now only a 4-5' SMB, as that's all that's above the waterline. So if you're in high seas or far from the boat (the reason for having a big SMB in the first place) then you're not getting the full benefit you were looking for in the first place

True,but also my 50lb 6 foot SMBS, when fully inflated, is rigid enough for me to hold vertically above my head and wave around. The thin flopper was only effectively a 4 footer.