DSMB Requirements

[MacLir]

Hi all. I am hoping for some clarification from experienced folks regarding required use of DSMBs on Red Sea liveaboards. We are planning a family trip next year for either the North/Wrecks or St Johns routes. Due to experience levels in the group (1 entry level Tech, 2 PADI AOW, 2 PADI OW), we are not considering the BDE route as we consider it beyond our collective skill level.

This will be our first trip to the Red Sea. We have not picked a boat yet. Prior liveaboard/land based diving has been New England US, Carrib., Hawaii and similar. All have boat diving experience well in excess of 30 dives.

I have seen conflicting posts on SB and elsewhere as to whether deployment of a DSMB at depth is required for the above itineraries. I have some experience with DSMB deployment, but only in limited training contexts; the rest of my group has no experience. All of us are, of course, familiar and comfortable with inflating and using SMBs at the surface.

Can anyone advise on what the standard practice/expectation is regarding use of DSMBs on Red Sea liveaboards?

Thanks!

 

[stepfen]

Maybe he is just exhaling. I have heard of another very experienced instructor and cave diver, George Vandoros, who often seems like doing exactly the same thing - constantly exhaling a small stream of bubbles.

It could be the case, BUT then the leak would have to stop every time he inhales (physically it is not possible I think to inhale through the mouth and at the same time exhale through the nose). The said leak hardly stops throughout the whole 3 minutes, while the guy is constantly breathing.

 

[TheRedBeanPanda]

Garry Dallas of RAID has a nice video on YouTube here at about the 1:13 mark.

Wow that guy does not move an inch. What does he mean when he looks at his computer and signals with two fingers before letting the DSMB go up?

A number of years ago, we switched to plate and wings so that we could better weight and trim students.

Does that not cause problems later on if they don't buy their own gear straight away and go on to renting jacket BCDs?

 

[TheRedBeanPanda]

Sort of related. I dive a back inflate BCD, it has wings like a plate but more built in stuff like pockets and padding. Anyway occasionally I'll dive somewhere far away and if it's not going to be dozens of dives like a liveaboard, and if gear rental is cheap or free I'll leave most of my stuff home.

Of course it's always jacket BCDs. I have never noticed the slightest bit of difference.

It sounds like you personally are an experienced diver and you have probably used different types of gear so I'm not surprised that it's easy for you. But if someone is just recently certified and learned their configuration with a backplate and wing and then suddenly elsewhere is given a jacket or vice versa, a lot of things are just different and they will need to make adjustments that might be hard for a newbie.

 

[wetb4igetinthewater]

But if someone is just recently certified and learned their configuration with a backplate and wing and then suddenly elsewhere is given a jacket or vice versa, a lot of things are just different and they will need to make adjustments that might be hard for a newbie.

It comes down to their training. If they were taught neutrally buoyant and trimmed, properly weighted through their entire course, then it would be a minor adjustment. Remember the key to trim is weight distribution. They should understand how to do it for themselves and sort it out within one or two dives (being practical here). The concept of center of mass and center of volume/displacement is universal.

 

[Sebek]

Wow that guy does not move an inch. What does he mean when he looks at his computer and signals with two fingers before letting the DSMB go up?

He's indicating the depth, 2.7m. (two fingers pointing up facing out for 2, poke for dot, two fingers sideways facing in for 7, flat hand moving horizontally for depth)

 

[TheRedBeanPanda]

It comes down to their training. If they were taught neutrally buoyant and trimmed, properly weighted through their entire course, then it would be a minor adjustment. Remember the key to trim is weight distribution. They should understand how to do it for themselves and sort it out within one or two dives (being practical here). The concept of center of mass and center of volume/displacement is universal.

Maybe it's because of the (non-) thoroughness of the training I had when it comes to weighting and trim, I'm just having a hard time imagining that someone fresh out of their OW would be able to do that (For example it took me 50 dives to figure out on my own that my weights should *not* go where everyone was telling me to put them ) Absolutely not questioning your experience as an instructor, though. We just need better training for everyone

 

[wetb4igetinthewater]

Maybe it's because of the (non-) thoroughness of the training I had when it comes to weighting and trim, I'm just having a hard time imagining that someone fresh out of their OW would be able to do that (For example it took me 50 dives to figure out on my own that my weights should *not* go where everyone was telling me to put them ) Absolutely not questioning your experience as an instructor, though. We just need better training for everyone

Well I'm not popular in some local instructor circles!

Yes the typical OW student was taught on their knees and will struggle. And is less likely to continue diving.

It is in the long term interest of everyone in the dive industry to teach open water divers properly.

My success rate of students who continued diving flipped when I started teaching neutrally buoyant and trimmed.

The problem is the short term revenue loss for the agencies from disqualifying incompetent instructors.

So many CDs/ITs, especially the stereotypical Koh Tao CD (who has me blocked from making comments on his YouTube channel) can't perform skills neutrally buoyant, trimmed, and not sculling.

These people crank out the instructors which is a huge source of revenue for the agencies

So I don't think much will change. The small segment of proper instruction will continue to grow but the overall market will continue to shrink