Want to practice SMB deployment alone - Safe?

[TSandM]

Well, he did say three to four METERS . . . which is just about safety stop depth, and where a lot of people would deploy a bag.

 

[g1138]

Well, he did say three to four METERS . . . which is just about safety stop depth, and where a lot of people would deploy a bag.

Doi
I deserve this -> :chairfight:

 

[mulla]

Hi All,

Thanks for the suggestions and tips and helping out a newbie diver.

Find someone who wants to practice SMB deployment and take turns.


Bob
-----------------------------------
I may be old, but I’m not dead yet.

Given my limited time in diving I don't really have that many buddy to choose from but will definately try to get them involved and share my SMB and take turns. Hopefully they don't mind sharing germs with me

Are there not any local dive clubs that have pool practice sessions you could go along to??

That's actually a good idea! I might ask at the shop / club where I got certified to see if I can join in their pool session for their next OW class and I will just stay in a corner firing missles

Hi Mulla,

First off it's great that you want to practice with safety items and get comfortable with them. To address some of your concerns, it really doesn't take much air to make the marker go to the surface. Since you're just practicing, put just a little bit in it that way you can easily pull it back down without the need to continually surface and retrieve it.

Once you get comfortable with the basic motions, you can practice putting more air in it and gradually reeling yourself up the line to the marker on the surface. Remember air expands as it rises, so the deeper you are, the less you'll need for a full bag at the surface.

While you're practicing that, it would be a good time to work on those neutral buoyancy skills as well. The line hanging in the water provides a great reference and that's one skill that will help you get some of the most enjoyment out of diving.

Finally I'm always a bit concerned when fairly new divers want to practice things solo. I know sometimes it's hard to work schedules out with a buddy, but at the very least consider having someone with you on shore as a 'bubble watcher' that can assist if something were to go wrong.

Good luck with your practice and welcome to the board!

Thanks heaps for the tip, will make sure I don't over inflate on trial runs. Will try to see if I can hook someone up to come along to do a smb practice and tour. Certainly don't expect to find any buddies that's willing to blow a cylinder of air just on smb practice.

Yes, the easiest answer is to get somebody else excited about learning the skill.

If you are using a bag that big, I wouldn't try to fully inflate it before letting it go -- full, it would be difficult to pull back down. Just put a couple of puffs of air in it, and that will be enough to take it to the surface, but still allow you to pull it down and launch it again.

Please, don't do this kneeling. For one thing, if you are kneeling, the bag is much closer to the all the bits and pieces of your BC, and it's easier to get stuff caught. If you are lying on your stomach or floating (even balanced with your fin tips) and keep your hands out in front of you, you are FAR less likely to get the line tangled and end up with an involuntary ride to the surface. And if you don't believe this can happen, it can -- Rick Inman on this board took a ride from 70 feet to the surface once, and wrote a report here about it.

Didn't know that kneeling can add to entaglement dangers! Will def make sure I'm horizontal before doing this. Thanks for the great tip!

Doi
I deserve this -> :chairfight:

That's ok, I get confused constantly when I see people claiming they've been to 100m only to find out that it's 100ft on my second read

Might explore the pool option with an OW class, and stick to just 1 or 2 test deployments on my buddy dives.

Thanks once again, great forum for sure

 

[KY]

Jeezz,,, cant believe some people... loads of hot air and hardly a word of advice amongst any of it...

Look, mulla,

Jump in the water as you are planning, but tie a knot in the dsmb.. make sure its nice and tight so you do not get any air migration.

Then sit under the pier and inflate to your hearts content. The fill in the DSMB wont be much, so you will be able to pull it back down to you, so you can dump the air, and start all over again... just make sure the knot is quite low down on the DSMB...

and before anyone argues, how much air do you actually put in a DSMB at 15 -20m?? hardly any, so, whats the difference??

ky

 

[herman]

Which SMB do you have? If it's one of the 3 footers, you can actually deploy it and then go negative and haul it back down. That's what we do when we want to do repeated deployments, rather than ascent each time to retrieve the bag. I'm with the prior poster -- repeated ascents, even in the shallows, can leave you feeling pretty rotten. BTDT.

As far as whether it is safe to be alone in the water under a pier -- the one thing that would worry me would be being under there with all that structure and line you aren't used to handling. A buddy could come in rather handy to cut you loose, if you got majorly tangled.

I did the same thing in my swimming pool (by myself) so I'm not going to jump up and down and say it's unsafe to be in the water alone. But ideally you do it where there are few, if any hazards.

While this is possible for a diver with large doubles or a drysuit- assuming they don't mind being squeezed, it is darn near impossible for a propely weighted single tank diver to do. If you can, you are grossly overweighted. The lift of a small SMB is in the 10 to 15 lb range, if a single tank diver can dump that much air from his BC he needs to work on weighting before the SMB.
Purposely overweighting at the start of a dive with the intent of deploying and retrieveing a SMB would not be a bad idea, is certainly doable and worth doing. However, a properly weighted single tank diver attempting to do so will fail.

 

[Elvistheking]

The other way I have heard to practice is to get a cheap second hand one then put a small hole in the top, you can then send it up and then wait for it to deflate and come back down before you re-inflate it and send it back up.

 

[MXGratefulDiver]

Hi All,

I've been lurking in the board for a while now, but couldn't seemed to find an answer to my question so I thought I might register and ask. Sorry if it has been posted elsewhere.

I'm a new diver with roughly 15 logged dives, with a mixture of boat and shore dives.

Have recently purchased an SMB and spool and watched some youtube videos on how to deploy it and sure does look easy enough when the pros are doing it. I have yet to try deploy it underwater myself but have done a few dry runs on how to hold it correctly with one hand and not to stick your finger into the spool etc.

I am wondering what the "danger" level is if I wish to practice deploying an SMB in shallow waters ~3-4m depth on my own? Plan to just jump in off a pier and duck under and practice while stationary.

Reason why I ask is, I wanted to just get into the water and deploy, retrieve and redeploy over and over again for as long as my air supply will last. I believe this would be similar to watching grass grow for any buddy.

Wish to get my deployment skills up quick, but if you guys believe this is not a safe practice I'm happy to just make one or two quick deployment runs each time I do a proper dive with a buddy.

OK, I'm going to give you some things to think about ... you decide what to do with them ...

First is that, at your experience level I don't (personally) believe you should be underwater at all without a dive buddy ... regardless of depth. The reason is simply that you're still adapting to an underwater environment, and I've yet to meet the diver who, with only 15 dives, has trained his awareness to the point where he can be concentrating on performing a skill such as DSMB deployment and still be aware of what else is going on around him. That's what buddies are for.

Second is that DSMB deployment is a skill I teach in my Advanced Scuba Diver class (NAUI's equivalent of AOW) ... and I frequently see divers with considerably more experience than you end up giving a classic performance in underwater macrame. Watching a video won't teach you how to maintain tension in the line while managing your buoyancy control ... and I can assure you that the line can develop an evil sense of humor if you allow it to become slack. I've sometimes had to "untie" a student who got it all wrapped up in their scuba equipment.

Finally ... even at shallow depth ... I won't even recommend an experienced diver go solo without some sort of backup gas supply. There's only one true emergency underwater ... and that's not being able to breathe. If something goes wrong, you have seconds to respond to it. And it's the rare new diver who remain calm enough to use those seconds wisely ... that's just something that comes with experience, practice, and confidence.

I applaud your desire to learn. Do it properly ... take a buddy with you ... preferably onw who has shot a bag before and who can watch you do it and provide feedback afterward on what you did right, and what needs improvement. As with any skill, even when you get it right, it can always be done better.

... Bob (Grateful Diver)

 

[MXGratefulDiver]

While this is possible for a diver with large doubles or a drysuit- assuming they don't mind being squeezed, it is darn near impossible for a propely weighted single tank diver to do. If you can, you are grossly overweighted. The lift of a small SMB is in the 10 to 15 lb range, if a single tank diver can dump that much air from his BC he needs to work on weighting before the SMB.
Purposely overweighting at the start of a dive with the intent of deploying and retrieveing a SMB would not be a bad idea, is certainly doable and worth doing. However, a properly weighted single tank diver attempting to do so will fail.

Actually this is not necessarily so. The bag I use for teaching has approximately six lbs of lift ... roughly the weight of the gas you're carrying in a full AL80 ... so if you do the drill on a full cylinder you can easily manage to pull it down if you're doing so at the beginning of a dive, when your tank is full (remember, you weight for a tank with just your reserves in it).

Also, there's no law that says you need to fill the bag completely. For practice all you need is enough gas to send the bag to the surface. And once you start pulling it down, Mr. Boyle becomes your friend ... the bag gets easier to pull down as it gets deeper.

When I teach this skill in AOW, we shoot the bag from about 20 fsw. After the student shoots the bag, I will pull it back down and wind up the spool so they can try it again and again. I'm normally wearing an LP95 single cylinder when I do this ... and it's typically about 2/3rds full at that point in the program.

... Bob (Grateful Diver)

 

[MXGratefulDiver]

Given my limited time in diving I don't really have that many buddy to choose from but will definately try to get them involved and share my SMB and take turns. Hopefully they don't mind sharing germs with me

Food for thought ... you shouldn't be diving with someone who's worried about sharing germs. How do you suppose they're going to react if you or they suddenly need to share a regulator? ... which, by the way, is another skill every new diver should consider practicing until they can do it without conscious effort ...

... Bob (Grateful Diver)

 

[String]

3-4m is the hardest place of all to inflate. OK if you have one of those silly tiny ones but hard to get them anywhere near full if you've got a full size one.

Best way to practice is have someone on the surface to deflate the bag so you can winch it back down and try many deployments.