Using a DSMB

Throughout the majority of my diving I have used a SMB (surface marker bouy) so am familiar with the procedures and hazards of being tethered to a bouy on the surface. However I have just bought a DSMB (delayed surface marker bouy, for those who dont know: u unroll and fill it with air at the end of the dive, it rockets up to the surface so the boat knows where u are)

I wanted to know what tips or precautions ppl suggest about using a DSMB? Obviously the first one is to only inflate it at a depth SHALLOWER than the length of your line, otherwise ur in for a wild ride!

don't know about DSMB, but i'm pretty familiar with DSM-IV......

And probably BDSM as well!

I've used my safety sausage as the DSMB on drift dives and it seems to work well. Just make sure to reel in your line as you ascend, and if you have marked your reel line it will give you a good visual on your ascent rate without having to stare at your dive computer.

don't know about DSMB, but i'm pretty familiar with DSM-IV......

I wonder....

You're not getting any help here, are you? I came in to learn something, but -?

I wonder if there's a Premium membership that blocks TF from posting on a thread??

That sounds slick. Where can you find them.

You're not getting any help here, are you? I came in to learn something, but -?

I wonder if there's a Premium membership that blocks TF from posting on a thread??

you're just jealous, don.

Throughout the majority of my diving I have used a SMB (surface marker bouy) so am familiar with the procedures and hazards of being tethered to a bouy on the surface. However I have just bought a DSMB (delayed surface marker bouy, for those who dont know: u unroll and fill it with air at the end of the dive, it rockets up to the surface so the boat knows where u are)

I wanted to know what tips or precautions ppl suggest about using a DSMB? Obviously the first one is to only inflate it at a depth SHALLOWER than the length of your line, otherwise ur in for a wild ride!

Sounds like you're going to be shooting the DSMB like a lift bag from depth. This is one of those things that you want to practice in shallow water before you try at depth. If your line is shorter than your depth you can always let it go. Real problem comes if you tangle yourself in the line while you shoot the bag. You're going to be hurting. Also make sure you look up to make sure you don't tangle anyone above you. Depending on depth you don't need that much air. One lung full is usually enough. The first one is free, when you breathe in again you're going to start ascending, so I'd just let it go then. If it's an open ended DSMB like OMS, you can blow into it or you can use your reg to fill it up. Remember, when you're about put air in the bag, take up all the slack on your line(this swill help prevent entanglements, look up, add air, and release.

Thanks ryvor some useful stuff. When I bought my DSMB it didn't come with a sperate reel, just 60' of line wound up. Would you recommend using a reel with it? I guess the main benefit is its easier to wind in whilst ascending than gathering it in by hand. What with the stuff I regularly carry (torch, slate, DSMB, knife) and the stuff Im planning on getting; rescue streamer, signal flag and pocket mask Im sorta running out of pocket and clip space.

Do ya reckon I need a reel? If its yes then I'll just bite the bullet and be ladden down like a pack animal, well at least ur weightless U/W.

A spool is actually better than a reel in this case. When you release the buoy, release the spool as well. It should simply sit in front of you and spin as the bag shoots to the surface.

A spool is actually better than a reel in this case. When you release the buoy, release the spool as well. It should simply sit in front of you and spin as the bag shoots to the surface.

I agree with Walter. Use a spool. It is better. I carry a spool with me in most dives and it fits nicely in my BC pocket together with my safety sausage/buoy. Halcyon and OMS make very good and inexpensive spools and they come with a clip and in various lenghts. Once you are ready to initiate you ascend, achieve neutral buoyancy at your depth, get the buoy out of your pocket and attach the spool clip to the end of the buoy. Then, put some air in the buoy (not too much. Remember it will expand on the way up) and release the buoy together with the spool. Make sure you keep and eye on the spool and let it roll until the buoy hits the surface.

I love to use a spool and a buoy to do safety stops specially on drift dives or when the water conditions are not the best.

yes, a small gap spool is best. But if you don't have one and have a small reel, you can use that too. Some people like to let go of the spool or reel when they launch it and some like to hold on to it. Reason you let it go when you launch is because if it fouls up you're not holding on to it. If I'm holding on to it and it fouls, I just let it go. I've seen one spool drop to the bottom because the guy blowing the bag couldn't grab it in time when it stopped. Luckily the bottom was only 15' away and we were just practicing. Try both, and do what you feel more comfortable with.

Good advise above. I recomend the spool for most applications. One thing that I did not see said that I feel is important is you need to have a cutting device(prefferably two) within quick easy reach just in case all goes wrong and you end up entagled in the line.
Whether you can let go of the spool depends on whether the DSMB has an open bottom or has a built in check valve. With the built in check valve you can use your exhaust or purge to inflate the DSMB and all the air will stay inside. If you have an open bottom bag you must keep tension on the line or the bag can fishtail on the way up and dump the air. It may also dump the air on the surface if you release tension and let it fall over. DiveRite and Carter both make excelent bags with check valves built in.

Jim

Good advise above. I recomend the spool for most applications. One thing that I did not see said that I feel is important is you need to have a cutting device(prefferably two) within quick easy reach just in case all goes wrong and you end up entagled in the line.

Good observation about the cutting device being handy! -ww

A spool is actually better than a reel in this case. When you release the buoy, release the spool as well. It should simply sit in front of you and spin as the bag shoots to the surface.

I agree with Walter. Use a spool. It is better. I carry a spool with me in most dives and it fits nicely in my BC pocket together with my safety sausage/buoy. Halcyon and OMS make very good and inexpensive spools and they come with a clip and in various lenghts. Once you are ready to initiate you ascend, achieve neutral buoyancy at your depth, get the buoy out of your pocket and attach the spool clip to the end of the buoy. Then, put some air in the buoy (not too much. Remember it will expand on the way up) and release the buoy together with the spool. Make sure you keep and eye on the spool and let it roll until the buoy hits the surface.

I love to use a spool and a buoy to do safety stops specially on drift dives or when the water conditions are not the best.

Good suggestions, but my opinion differs in one respect. I don't use the double-ender clip to attach the buoy to the spool, I simply thread the looped end through the attachment hole in the bottom of the sausage (and mine's slightly weighted at the open end to help keep it from dumping air). That way I can use the clip as a crank when reeling in the line on my ascent.