DSMB requirement?

[gopbroek]

When/where is the usual time/place to learn to deploy a DSMB? I'm planning to learn in Key Largo in April provided we have calm waters. In particular, I'll be hiring a private instructor to both be the DM and help with learning the deployment skill. I want to learn so I could deploy a DSMB in Cozumel but I think I should get some practice without the current first.

In calm, but not dead calm, waters when relaxed and not low on air or in an emergency and towards the tail end of the dive where you have the ability to surface to restow the buoy and go back and try it again. It is deceptively simple and folks laugh at others when they loose control of the line on videos. In reality the first time you have to deal with a bunch of loose line on your first or 100th deployment it like trying to getting tooth paste back in a tube. When deploying the buoy it is deceptively simple but what surprises many is how quickly the velocity increases as the tube rises and the gas volume expands, you must keep tension on the reel and that is where it can go south quickly. Kind of like learning to cast a level wind. Like any other basic skill it really just takes practice.

 

[ggunn]

In calm, but not dead calm, waters when relaxed and not low on air or in an emergency and towards the tail end of the dive where you have the ability to surface to restow the buoy and go back and try it again. It is deceptively simple and folks laugh at others when they loose control of the line on videos. In reality the first time you have to deal with a bunch of loose line on your first or 100th deployment it like trying to getting tooth paste back in a tube. When deploying the buoy it is deceptively simple but what surprises many is how quickly the velocity increases as the tube rises and the gas volume expands, you must keep tension on the reel and that is where it can go south quickly. Kind of like learning to cast a level wind. Like any other basic skill it really just takes practice.

The first time I tried it I was just like the guy in those videos, plus, between the focusing on trying to get the thing inflated and dealing with the string, I lost track of my depth and ended up at the surface amidst a tangle of yellow string. It was not pretty. I recommend performing your first deployment on a shore dive in calm water with a hard bottom.

BTW, when you first get a finger spool, unwind it completely and tie the end of the string to the spool. Mine, at least, didn't have the line attached when I bought it; I dropped the spool during the aforementioned melee and I never saw it again.

 

[boulderjohn]

If you check out videos of DSMB deployment, you will most likely see the most difficult way it can be done. That is because most of the people doing it on the videos are doing it for technical diving with a belief that it must be done while maintaining horizontal trim at the precise depth from which they are deploying it--no change allowed. In my tech classes, that is how it is done, but if you watch a typical DM do it, they are always in a nice, comfortable, vertical position, with not a big concern about rising or falling a couple feet. That makes a surprising difference. For most people, there is no need to maintain horizontal trim.

 

[deepsea21]

I'm not going to say Cozumel dive ops should "require" a DSMB or SMB as my wife and I dove for years without one and if you are a diver who descends, stays and surfaces with a group the odds of needing one are small unless for some reason you became separated from the group and had to surface on your own. In areas with a great deal of boat traffic (like Cozumel), the #1 concern is a boat/prop hit when you are in that last 5' range to the surface and descending upon hearing an approaching boat with a light tank and carrying just enough weight to hold neutral at the end of a dive can be tough. For those who are concerned about separating from a group or have bottom times that allow them to stay longer than the group I believe a DSMB is an absolute must have and it doesn't take a great deal of instruction or practice to learn how to properly deploy one. I remember my 1st deployment when I failed to properly attach my reel to the DSMB and watched it soar to the surface like a kid who lost his balloon. Lesson learned... tie it on to the line on the reel and make it one, simple package to deploy. With regard to "bird-nests" forming as the reel or finger reel spins when the DSMB hits the surface... The simple cheap plastic finger reel with the numerous holes in it is the best to avoid that. The holes in the reel are not only there to clip and secure the line but they create drag in the water as it is spinning and the light weight of plastic stops the reel from spinning much faster than a heavy metal reel spinning. For casual diving the best DSMB purchase I made thanks to the advise of others on Scubaboard was the following which allows for multiple inflation options, has an over-pressure release valve and can be filled from its bottom via a quick shot from your secondary:

Blue Reef Diver-Below Deluxe 4' (1.22m) Surface Marker Buoy

And the cheap yet great reel:

Blue Reef Finger Spool Reel

Having learned the hard way and upon the advise of others, first thing you do is cut that plastic clip off the DSMB, eliminate a step in deployment, and permanently attach the reel line through the DSMB's loop where the clip was. Wraps up into a small package and it becomes quite fun to deploy while providing a great deal of safety at the same time. Even if you chose to carry just enough weight to remain neutral at the end of a dive you just pull on the line at the bottom of each exhale and that causes the DSMB to pop up and stand tall with each breath for boats to see as you are approaching the surface. Once on top, you can hold it nice and high and at night don't forget your light that you can shine on it while on the surface.

 

[Prop Joe]

I carry one. Gotta have one up North, way North or East side. I also carry a Lifeline radio/gps after being left on the bottom in La Paz (long story). Never hurts to be prepared. We came to the surface in January to some rather "sporty" conditions in the south. I could look up at the SS and knew it was going to be a challenge to get back into the boat. I was just about to deploy my green SMB at the surface along with Liang's but Thomas beat me to it. We surfaced as a group and had two SMB's one green and one orange. We waited a bit but the captain saw us. Port was closed after we had rolled in. 90+ minutes later after we rolled in the port was closed. At least we got one dive in and recovered the group as one. I would not have wanted to try that as groups of two in those conditions...

 

[gopbroek]

The first time I tried it I was just like the guy in those videos, plus, between the focusing on trying to get the thing inflated and dealing with the string, I lost track of my depth and ended up at the surface amidst a tangle of yellow string. It was not pretty. I recommend performing your first deployment on a shore dive in calm water with a hard bottom.

BTW, when you first get a finger spool, unwind it completely and tie the end of the string to the spool. Mine, at least, didn't have the line attached when I bought it; I dropped the spool during the aforementioned melee and I never saw it again.

How true , who actually unwinds one to see if the line is actually attached. I have retrieved spools for DM's who learned this lesson. For deployment training, with a finger spool, I would suggest not only ensuring the end of the line is attached to the spool but after rewinding it and then play out 40' and dip a loop through the side holes and reloop it back to create a stop. this way it will not play past 40'. Then rewind it and at 15 - 20' tie a simple small loop in the line as a SS depth marker. Then practice deploying it at 25-30' where ever you feel comfortable but remember after practice to remove the 40' stop loop. Just my observations.

Post edit, after practice remove the 40' backstop loop!!!!

 

[ggunn]

If you check out videos of DSMB deployment, you will most likely see the most difficult way it can be done. That is because most of the people doing it on the videos are doing it for technical diving with a belief that it must be done while maintaining horizontal trim at the precise depth from which they are deploying it--no change allowed. In my tech classes, that is how it is done, but if you watch a typical DM do it, they are always in a nice, comfortable, vertical position, with not a big concern about rising or falling a couple feet. That makes a surprising difference. For most people, there is no need to maintain horizontal trim.

FWIW, the videos to which I was referring are the ones which show the ways NOT to successfully deploy a SMB. My wife, who was watching from a few feet away, nearly drowned laughing at me.

 

[ggunn]

...dip a loop through the side holes and reloop it back to create a stop. this way it will not play past 40'.

I won't be doing that. If I happen to need to deploy it below 40' I don't want it dragging me up when it hits the stop.

 

[gopbroek]

I won't be doing that. If I happen to need to deploy it below 40' I don't want it dragging me up when it hits the stop.

Temporary for training purposes, it must be removed afterwards. Its a back up in case of a drop or overspeed reel.

 

[amoses]

Almost any Cozumel DM could show you how to deploy an SMB from depth.

wouldn/t you need a line and reel to do that though? Or not? I have always seen people using line and reel when deploying them from depth. And so far, I just haven't carried all that. Just the sausage part in case my boat doesn't find me for some reason