First time DSMB

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noblesix

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Dear fellow divers,

I'm about to buy my first DSMB. I've seen different types of them but I have few questions to ask:

1. What color is your DSMB line?
2. What is the minimum line length for recreational divers?
3. Which one is easier; octo-inflated or oral-inflated DSMB?
4. What is the length of the DSMB suitable for recreational divers?
5. Is it really necessary to carry a spare DSMB?

Thank you,

Dee
 
Based on your questions I strongly recommend you seek out and instructor and spend some time learning how to use a DSMB properly. Although it is a relatively easy process once you know how and practice a bit in a controlled environment, it can be dangerous and pose a serious entanglement hazard (to you and your buddy) if you don't know what you are doing. To answer your questions in the meantime...line colour really isn't important, although some people like high visibility orange, green or yellow line. The length of line depends on the diving your are doing, if you just want to deploy at a safety stop then 75' or so would be fine but if you may at some point want to deploy at depth and use it as an ascent line then you will need quite a bit more line. Most recreational divers are more comfortable inflating using their "octo" since it means they don't have to remove their regulator from their mouth. The best length is a function of where you dive...in the open ocean you will want a larger DSMB to be seen in large swells, in a lake you can get away with a smaller one. I don't know anyone who carries a spare.
 
1. Orange, but my "Oh Sh!t, come help me* safety sausage is green
2. Depends on what depth you're going to shoot it from. I prefer a 100' spool, but I might need to shoot it from a 30 or 50' stop. As a cave diver, I just grab whatever reel is appropriate for that dive, and one doesn't live permanently attached to the dsmb.
3. Depends on how big it is. I orally inflate my dsmb, but it is very small. I also orally inflate my big ass one, but that is closed because it is designed for surface use.
https://www.deepseasupply.com/index.php?product=85
4. depends. If you are using it as a dsmb, then I don't recommend going more than 1m because you are shooting it up to let the boat know something. If you want a safety sausage, then 2m, but that is too big to realistically shoot from depth. The deeper you are the easier those are to shoot, but they're still excessive.
5. no, but I recommend carrying 1 dsmb, and 1 safety sausage
 
delayed surface marker buoys are deployed from depth to indicate something to the surface. In tech diving it is usually "i am at my last stop" and because the boat has your dive plan, they know to expect you up at some point in time. On tech dives it isn't uncommon to carry multiples for the team so you can send up slates with stuff written on them if you need something brought down to you, extra deco bottle usually for big dives if something bad happened, or to prep them to have surface O2 ready etc etc. Their reels/spools should also be knotted for depth so you can use them as a depth gauge for decompression in the case of drift dives, or blue water decompression with a computer failure.

Safety Sausages are for sitting at the surface when you got lost and you want someone to come get you. For this you want one as big as possible, preferably with some sort of strobe on top, radar tape inside of it for the USCG, and preferably green over orange for vis at dawn/dusk. These are not deployed at depth because they are so damned big and are for an emergency only.
 
My personal equipment:
1. Orange/white/yellow. I have several spools.
2. 25m, 30m and 50m on different spools.
3. Octo-inflated
4. Buddy smb.
5. Min 2 and even 3 when in really open water.
 
This is the general advice I give to all my students......
Get a 4-5' smb, they are easier to fill, retrieve, practice with and inexpensive.
Get a 100' spool with a 4" double ender. Line color doesn't mater.

This is a low cost option, allows the basics to be practiced and is applicable for a very wide % of situations. Once you become proficient then you can analyse your dive, objectives and surroundings and choose your dsmb's.

Watch this video on how to properly deploy one.....
 
My recommendation is to get one that allows the following inflation methods;
Mouth
Octo
Inflater hose

All DSMB must have a relief/dump valve so when you use them at depth they dont blow up as they rise to the surface. Dont buy a cheap nasty one (and there are some that are just cheap plastic bags). Quality material means they last and work when you need them.

Mine cost about $50AUD and is good quality 4'. My yellow was about same price from Pirhanna dive Mfg and I think is 5'. Both have an inflater hose/mouth inflater tube, relief/dump valve and ducks bill for inflating with reg that seals on the surface if the DSMB falls over.

I have 2 for tech diving, (although for recreational one is fine). With tech in my part of the world;
Orange means here I am doing my deco
Yellow means I am in trouble, there is a slate attached to the DSMB with my problem.

I take 2 45m (130') finger spools, and if I am diving deeper take one I can deploy from the bottom (in case I need to ascend blue water or in a current so I show the dive boat where I am before I get into the current during deco).

I always deploy during deco or a safety stop, and mainly to practice as they can be dangerous if you get tangled in one while deploying, or if you deploy with too shorter line, as you can be pulled up to the surface. Practice as often as you can.

If you get it tangled around the spool and it starts to pull you up, LET GO! You can always recover the DSMB later (usually the boat does for you). If you dont let go it WILL pull you up.
 
Some good advice here. My little contribution.

1. Some practice's change due to local custom/requirements.
2. Orange[1] = OK, ascending, decompressing
3. Yellow[1] = problem (normal identified by a slate attached)
4. Line, enough to deploy from seabed + 20%. (Spools are generally mid water). In tidal waters we tend to deploy from the seabed before ascending, so the boat can track you in the current.
6. If deployed from depth, a little inflation goes a long way!
7. DO NOT have the line attached to you! Be prepared to ditch reel and line if you have a tangle or other issue.
8. Minimise loose line in the water and keep it clear of the divers.
9. Do have a cutting tool

Gareth

[1] colour designations are local, in this case UK. Also note orange is easier to see when on a boat looking horizontally, yellow is easier to see from above (helicopter).
 

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