Did I do it wrongly ????

[animian2002]

My diving buddies and I went on a diving trip lately, and as usual, we always take turn to practice deploying of surface marker. This particular dive, it is my turn to deploy and so as usual I took out my Spool and AP Valve (Self sealing) and did what I was taught to do ie switch to backup, use primary to pump enough air into the SMB to be able to control it and not let it run away. When I done with all the necessary, then I released it and made my ascent slowly.

When we surfaced, we saw the speedboat coming toward our direction and as the boatman helped us onto the boat, he laughed and made a comment "Your SMB so "small" and had so little air inside, very hard to see from far". At that moment, I just laughed along with the others but at the end of my brain, I knew the reason why it is small. It is because I have only partially inflated it for I need to be able to control it underwater and since you, the boatman is already on your way to us, why should I fully inflated the smb on the surface :icorolley

BUT as I think back when I took my AOW, we were taught to just pump air into SMB and let go..and at the surface,the boatman will be able to see a fully inflated SMB. BUT now, like what the boatman had said, my semi-inflated SMB might take them awhile to spot.

A simple, harmless comment from a boatman made me :thinkingo did I do it wrongly :dontgetit or am I really lousy with controlling my SMB underwater to the extend that I only inflated alittle and that resulted in the boatman having difficulty spotting it on the surface.

My question : Is there any way to improve it :06:

 

[Snowbear]

did I do it wrongly

Nah - he did spot it didn't he? As you noted, if you surfaced and not yet been spotted, you can always inflate it more.

Is there any way to improve it :06:

Improve what? How much the SMB is inflated when it gets to the top? Sure there is - inflate it deeper

In my tech1 class the instructor didn't like us using drysuit inflators and asked that we orally inflate the bags. From 70', 1/2 a lungfull was enough to have ~2/3 of a 50# liftbag sticking out of the water. Now that I'm not in class any more, I've gone back to using my DS inflator for CC bags or the primary 2nd stage for OC bags

 

[lairdb]

My diving buddies and I went on a diving trip lately, and as usual, we always take turn to practice deploying of surface marker.

[...SMB only partially inflated on reaching surface...]

Actually, though Snowbear points out that it was successful, in that the boatman saw it, I think it's a fair question.

Let me state it a little differently, though: "animian2002 asks: 'One way to have my SMB fully inflated when it reaches the surface is to inflate and deploy it while I am at a greater depth. If I want a fully inflated SMB deployed from a shallow depth, I must put more air in it than I'm used to. What are some techniques for doing so that will help me still maintain good depth control?'"

One example (disclaimer; I haven't tried this) that I saw in another thread was to use some air from the wing to inflate the SMB, theoretically leaving you net-neutral (at least, until you let go, at which point you're negative.)

I was taught to start out slightly negative (staying level through deeper than usual breaths), and fill the SMB while performing a deep exhale (again theoretically staying net-neutral), also that key was filling-and-firing the SMB in one quick operation, so that it didn't have a chance to tow me up.

Other thoughts from the more experienced or BSAC/CMAS camps?

 

[animian2002]

One example (disclaimer; I haven't tried this) that I saw in another thread was to use some air from the wing to inflate the SMB, theoretically leaving you net-neutral (at least, until you let go, at which point you're negative.)
/QUOTE]

:small: can't do that cos there is no air in my wing when I dive and I have no idea how to do that too :11ztongue

 

[SDAnderson]

Your concern seems to be that the boat may not be able to see/find you with your current procedure for deploying a marker. You want your smb to be more visible, which can be accomplished several ways:

• Put more gas into it by altering your deployment procedure at your current depth. Of course, you run the risks of entanglement and a runaway bag, but that's what buddies are for.
  
• Put more gas into it by deploying deeper. Putting Boyle's Law to work will allow you to maintain the same basic procedure while ending up with more gas in the bag.

I'd suggest that you consider a change in approach to the problem that I've only recently been experimenting with: deploying before I leave the bottom. Not only does this assure that the bag will have a maximum amount of air in it when it hits the surface but it has the added benefit of making sure that the smb hits the surface in the immediate vicinity of the boat. No more problems with the boat having to watch for and follow a bubble trail, the smb is on the surface, fully inflated while it's right next to the boat and if the driver can't see that, there are other problems that you can't solve from the bottom.

Other than meaning that you'll be carrying more line (and maybe switching from a spool to a reel) there isn't any fundamental change in the methodology of deploying the bag. You can still inflate orally (my first choice) or off your primary (my second choice) or use the inflator (last place in my pantheon of choices) hose. I don't buy unhooking the dry suit hose - up here in cold water that's too hard to do with heavy gloves on.

 

[GDI]

You do want to get as much air in the bag when at the surface as possible not just for the stiffness that the bag (or SMD) will have, thus hopefully the boat will notice it better but also to ensure that waves crashing down onto the bag will not collapse the bag. There are large SMD sausages out there that have comparable lift to that of a lift bag and provide a much larger and higher profile for the chase boat to locate and observe. You need to deploy the bag based on what the environmental conditions are. Harder rougher conditions you want that bag as close to the boat as possible.

 

[PatH]

Is there any way to improve it?/QUOTE]

Consider a smaller SMB (I carry a Halcyon 3' SMB in my pocket with a 100' spool ready attached). They fill on one breath of air and thus can be deployed easily from any depth. If you are orally inflating them you stay bouyancy neutral while filling the bag (air goes from lungs to bad, which you are holding). Then you release the bag before breathing back in. You can thus stay level through the entire process (with practice !! ). Just keep a little downward pressure on the line so the bag will stand proud of the surface.

Just an idea...