At what depth to deploy DSMB

[Crowley]

I deploy mine at about 7m as I'm approaching my safety stop - as per previous discussions, it's an SMB that can be inflated from the low pressure hose, or orally, or with my alternate through the non return at the bottom and also has a dump/overpressure valve to prevent un-necessary explosions.

You should be able to deploy an SMB whilst correctly weighted at 5m/15ft - if you have to wear extra weight to deploy an SMB, you are incorrectly weighted. Simple as that. Dump the last remaining air in your BCD - which should be minimal, take a deep breath out, and as you sink a little, inflate the SMB. If you're inflating orally, take a big deep breath in as you sink and blow into the bag - as we've discussed before, this has less effect on your buoyancy control because you are just transferring air from one place to another. Done.

Cheers

C.

 

[TSandM]

Crowley, I don't know if your comment was directed at my statement that one might want to weight himself a bit heavier if deploying an SMB or not. But my statement wasn't that you needed to be heavier to DEPLOY the SMB. You DO need to be a bit heavier if you are going to put enough downward pull on the line to make the bag stand, unless you want to spend your shallow ascent swimming yourself down constantly. I found this out the hard way

 

[Tortuga68]

You DO need to be a bit heavier if you are going to put enough downward pull on the line to make the bag stand

Yes and no... you can just pull up and down on the line, makes your balloon pop up and down, like it's waving to the boat to come and get you

 

[DevonDiver]

If there are waves... the bag is gonna bob anyway...

..if you're hanging off the bottom of a tight line, then you'll be dunkin' and jiggling up and down like a demented puppet.

I view the bag & reel as a method to provide a visual reference (yes..even though I may be holding the reel and winding on ascent). I don't teach, or recommend, for people to use them as 'buoyancy compensators'.

 

[Crowley]

no TSandM not directed at you at all - I am responding to what others have implied

I just think that sometimes, simple subjects become a bit too complicated and get over-analysed - SMB deployment takes a bit of practice, but is actually quite easy, and the implication that a diver needs to carry extra weight in order to deploy one is a bit silly. We all have our moments with SMBs - I used the wrong clip once and er - well, I ascended!

Yes, you don't want to inflate a balloon and have it whizz you to the surface, but as tortuga says, you can pull a bit, and I think that people forget sometimes that you can actually have a physical effect by using your own body as well as your buoyancy control, be that swimming downwards or just pulling on the rope.

I do it three times every day so I don't worry too much about it, but I do respect and understand that most people don't, but I also firmly believe that diving ability should not be compromised by concerns about sending up an SMB - a little bit of practice is necessary, but planning a dive around SMB deployment should not be an issue.

Cheers

C.

 

[Nightwitch]

It depends where I am diving.
When I am diving at Manta bowl where the surface conditions are often horrible and sometimes deteriorate during the dive, along with a ripping current, I will send it up as I leave the bottom at about 15 metres...this gives the boat crew more time to track the group, they expect us to be up at about 10 minutes after they see the marker so can position themselves correctly for a speedy pick up
If I am diving a more sheltered spot I will send it up from 5 metres on our safety stop, again the boat crew knows that at these sites we will be with them in less time but that they can stay away a little as the surface conditions are better.

I am still practicing with methods but currently favour the finger spool over the 5 metre line as then it leaves me more options for deployment depending on whats happening during the dive..but especially on Manta bowl when I often have to ascend with someone who is having trouble before the boat crew is expecting us..

Depends where I am..

 

[wedivebc]

Has anyone tried this, in order to mitigate buoyancy issues while ascending with a deployed SMB, and reeling the line at the same time?
Most SMBs have approx. a 30# lift or greater. So, if you deploy from a safety stop, or deeper, you can completely deflate your wing, wind yourself up the line, then re-inflate on the surface. I've never tried it, but it would seem to save having to think about venting during the ascent, while you're dealing with the spool, and also winds the line up on the way.
Might be a foolish idea... just a thought...

Not exactly but I use the air from my wing to inflate my SMB. That way I am neither positive nor negative when getting the bag ready to deploy. As I shoot the bag I replace the air in my wing to become neutral again.

 

[Pauly854]

Ok, stupid question time: As I have mentioned in other posts, on other threads, I have been diving for several years, but have strictly been in quarries, lakes, ponds, mud puddles, etc. I am going to get an SMB for an upcoming boat trip to Florida, but have never had the occasion to use one, see on used, or know anything about them. So m stupid question(s) is: when do you use them? Is there usually one per group? One per diver? If my buddy and I surface before the rest of the group, should we deploy. Only in emergency? Basically, what the heck are they for?

Educate me, oh knowledgeable ones. Thanks

 

[Baconator]

Ok, stupid question time: As I have mentioned in other posts, on other threads, I have been diving for several years, but have strictly been in quarries, lakes, ponds, mud puddles, etc. I am going to get an SMB for an upcoming boat trip to Florida, but have never had the occasion to use one, see on used, or know anything about them. So m stupid question(s) is: when do you use them? Is there usually one per group? One per diver? If my buddy and I surface before the rest of the group, should we deploy. Only in emergency? Basically, what the heck are they for?

Educate me, oh knowledgeable ones. Thanks

Around here we use them every time we surface. So the chaser boat can see you and so that other boats can see you and don't run you over (hopefully, though I've had an experience where a big bangka ran over my DM's smb...)

I always have mine with me even if my buddy has one as well just in case I get carried away by a current, I think it's a good idea to at least have one per buddy team.

I deploy mine at around 10m so I don't end up getting carried with it if I forget to unclip it from the spool

 

[syntaxerrorsix]

Ok, stupid question time: As I have mentioned in other posts, on other threads, I have been diving for several years, but have strictly been in quarries, lakes, ponds, mud puddles, etc. I am going to get an SMB for an upcoming boat trip to Florida, but have never had the occasion to use one, see on used, or know anything about them. So m stupid question(s) is: when do you use them? Is there usually one per group? One per diver? If my buddy and I surface before the rest of the group, should we deploy. Only in emergency? Basically, what the heck are they for?

Educate me, oh knowledgeable ones. Thanks

A fair amount of the dives on the East coast are either a drift dive with a flag or tied off to the wreck.

Most folks carry a safety sausage for recreational dives and only inflate them if they end up alone on the surface. Most operations put groups of divers in the water with a flag. So you are either going to be with a group and a flag or coming up the anchor line and climbing back on the boat.

We use a DSMB to mark the start of our deco as we drift off the site so the boat can follow us and that's about it.