SMB for ocean dives

[eelnoraa]

I am currently using a halcyon 3.3ft smb. It all and small, very easy to deploy on ascent. For my local divng, it has been useful.

However, I was just diving in Kauai. Ocean was quite choppy, wave was big. No one on the boat paid any attention to it, and later I found no one actually saw it. So I wonder what kind of SMB I should use in that kind of water. I saw the guides use some open bottom 6-10ft long smb. I borrowed one for a few dives and found deploying such a big smb is very messy at 15-20ft. And it is impossbile to have it fill properly.

So what is the DIR's view on this? should I have both size? deply the smaller one on ascent, then fill the big one to get the boat's attention?

 

[Ben_ca]

One part of the equation is this: Was the boat crew actually looking for you?

I have used the small H SMB on tech dives in Monterey and Big Sur without a hitch. I think the difference in our situations is that when we are doing a tech boat it is a "live boat" with a limited number of teams. We give the captain and estimated run time and when he should expect the SMBs. We also coordinate with the other teams so that the bag shoots are synced so that the SMBs hit the surface around the same time. Now if it was a recreational charter and the instructions are to return to the anchor line that might be a different story. That being said I have lost the anchor line in the past and put up the SMB for the ascent and the crew was looking at me asking for an OK when I finally broke the surface... so in that case I guess it worked also.

 

[sotgecho]

We recommend on the boat to use what is appropriate for the conditions at hand. With that being said; I carry the 3ft smb in my left thigh pocket and a 4.5ft in my mc storage pack. I deploy dependent on conditions.

 

[PfcAJ]

I carry 2 on dives where the waves are a bit larger (which, admittedly, isn't often because ocean diving sucks or if I feel I'll really need an SMB. One smaller one, and a bigger, wider, taller one. If conditions are anything other than great, I just use the bigger one, nbd.

 

[lamont]

While you shouldn't use an SMB to assist your buoyancy control, if you don't put a little bit of downwards force on it, it'll tend to flop over and lie horizontally instead of stand up vertically which doesn't help the boat track you.

 

[TSandM]

If my dive plan included shooting a 6' bag, I'd do it at much greater depth. They are a pain to shoot from the shallows. But then, of course, you're stuck dealing with the bag, and if you're multi-leveling the dive, you don't really NEED to shoot it at depth.

I have yet to have a boat not see my 3' bag, but that's assuming a) I'm somewhere in the vicinity of the boat, and b) they know what they are looking for.

 

[g1138]

I've been DM-ing for one of the local Monterey boats during GUE tech dives on several occasions. We're given an estimate time of when the GUE team would be sending up their 1m Halcyon bags. In any case, we're actively looking for bubbles and bags all the time. Usually we have to keep track of 2-3 teams, 2-3 bags.

In rough conditions, it's much easier to see the 1m bags if you're elevated on the boat. On a clear day with small white caps I can still pin point the 1m bag a football field away, although I'm looking for it. If I were sitting at the bow of the boat instead of up in the wheel house, I'm sure it would be much harder.

Keep in mind however that a bigger bag is useless if it doesn't stand. I think anything bigger than 1m is usually too top heavy to be kept upright when in 0-trim and neutral buoyancy. The only time I've seen a DIR team use a bag bigger than 1m was a Halcyon 4.5ft CC bag. It never stood upright once. Never even quivered once, it just laid flat the whole time. I lost sight of it whenever small swells came in front of it, and we were pretty close too. So from far away in crummy conditions it would have been completely useless IMO.

Assuming you can keep it upright, the height of 1m is enough, it's the thickness of the tube that makes it hard to spot.
My advice to you is to get a wider SMB to use in rough conditions, preferably closed or at least baffled (although my baffle developed a severe leak on my Blue Reef SMB, even with regular inside rinsing).

You can get the usual 6ft x 6in SMB or the 4.5ft Halcyon CC SMB and simply inflate it enough to stand at roughly 1m. With my 6ft x 6in SMB I usually have to exhale a full breath at 20ft to get it to stand 3ft. When you get to the surface you can always inflate it fully if needed. Even with a baffle leak, your SMB will still hold air if you keep the lower portion submerged.

Of course it always helps when you shoot near the boat.

 

[TSandM]

g1138 makes a good point -- if you parse your weight so closely that you are neutral at your shallow stop at the end of your dive, you won't easily be able to make your bag stand up, unless you are swimming small circles, head down. It doesn't take a LOT of tension on the bag to make it stand (at least the 3' ones) but it does take some.

 

[fdarden]

I am more of a one size fits all guy, and I have never needed more than one SMB, and that is my 10 foot tall bright orange Highland Scuba SMB. I dive on the east coast of Florida 3-5 times per week, both rec and tech, and I ALWAYS carry at least one. Usually I also carry a lift bag, for redundancy and the day I find my priceless treasure on the ocean floor! It does not take much chop to make smaller SMB's disappear completely. The 10 foot one will not. Dont be afraid of it. Its simple to shoot, and easy to manage. I have no issues shallow or deep. works like a champ. Get yourself a nice thumbspool to go with it, and you will be set for anything. I usually dont wonder if I will be seen. You want this not only so your buddies can find you in rough seas, but so that other boats dont run you over, and rescuers (depending on the situation) see you!! The only downside is that in a stiff wind it may have the tendency to try to pull you along at depth, if you were say using it in lieu of a dive flag on a very windy day it could become annoying.

 

[eelnoraa]

Thank you all for your advices. All points well taken. In my local water, especially diving with GUE team on the Escapade, I don't worry about this at all. The team, the crews and the captain know what to expect. The 1M smb is usually good enough.

The problems I have had all from when I was diving in destination, when I ascent away from the boat, and involving choppy sea or surface current. The ops expect everyone to return to the anchor line and ascent, so I guess no one pays attention unless a group fails to return within given time limit. Yeah, the crew may not be looking for me. I just wonder what is a better method to get someone's attention, especially when I need the boat to come get me.