I just returned from a dive trip to Mexico where I could leave my DSMB at home: Full cave training. Got plenty of practice with reels and spools though. 😉 That said it's definitely worthwhile to practice DSMB deployment at various depths until you become quick at it and can do it without losing buoyancy or situational awareness. Start at 5m during every safety stop then start deeper. I prefer closed bottom DSMB. They do require you to use your mouth or inflator hose to inflate but don't lose gas on the surface and can be used as a life raft. Mine has a loop at the top and bottom so I can use a double-ender to connect both ends into a loop so it becomes a life preserver.
I used to dive 20 years ago, and just looking to get back into it. I always used a reel with my DSMB. Following launch, I liked to be slightly negatively buoyant, and then wind the reel in for a very controlled and steady ascent. I have never tried using a spool.
Not sure I'd recommend launching a DSMB from 40m... 15m is plenty soon enough... Great advice on launching though... exhaled gas really is the best way... means you can also launch a DSMB if someone is sharing your air. Great video.
Why destroy a DSMB to practise? Just tie a knot into it relatively close to the bottom. It will only partially inflate and you can pull it back down because it has very little lift.
Good idea, but you don’t get the full impact of filling a DSMB and launching it properly. I have seen people do this and nail the practice, but it all goes wrong when they attempt to fill a full-size DSMB. You can get a very basic DSMB for under £10-15 to use for practice.
@@ScubaDiverMagazine Fair point. I wasn't trying to say that you shouldn't practise with an "unknotted" DSMB after you nailed the practice knot, so I can see that people f it up if the first time with a full DSMB is the real deal.
i purge my octo to fill my smb but i find i don't have enough hands. I'll definitely try the used gas from my primary next time. i always thought you had to have enough pressure to push air through the hole at the bottom of the smb.
I have used several DSMBs with the primary-exhaust method, all obviously open bottom, some with a pull dump valve, with no issues. Just takes a bit of practice holding it in the right position, and make sure you hold your hand with the spool in out in front of you to keep the line well clear of any snag hazards.
It is interesting how DSMBs are treated during training. During my OW and AOW, and my Solo course, launching a DSMB was required. A dive buddy of mine, AOW, has never shot one. We both trained within the last 1.5 yrs. Different schools, but both on Canada's West Coast. She now has ordered one, in her colour, and I have told her that I will help her learn how to deploy it. The one thing to remember about spools though; if you get the nice shiny, sexy, metal spool; if you let go during deployment, the spool will unwind itself to the bottom or the end of the line. If your spool is a Delrin, or a "plastic" one; if you let go during deployment, the spool will simply unwind in front of you, and one can easily re-aquire the spool while it is spinning. I have used and prefer the exhaust method as well as a LP inflator hose I have on my pony, for exactly that reason.
Great video Mark as always. As a DMT, I always carry a DSMB on me with a reel ( and knife / cutting device ) on me for all dives. I use a DSMB with a LPI inflate option as well as the open bottom. Last week I was diving under a pier with a group of friends ( 4 divers in 2 groups of 2 ) myself and my buddy where diving with the other dive team, we turned around to start heading towards shore when the other 2 divers shot off in front of us kicking up the viz. We searched around for them for 1 minute as per the rescue training, surfaced to find them and couldn’t. Myself and my buddy surfaced and did a surface check, then went back down, went to the right of the pier and shot a DSMB up from 5m which enabled the other set of divers find us and we finished the dive via a surface swim where I then had to use my cutting device to cut my buddy free from fishing line. I have since spoke to multiple instructors and other dive pros and they’ve said the same thing as you. If the proverbial hits the fan. They’d rather have the gear on them and not need it. Then not have it on them and need it, A cutting device, DSMB, and Torch should be mandatory on all dives I feel as you never know when you may need to use one, let alone all 3 on a dive. As stated before great video, your videos, along with simply scuba, Divers Ready, and The Dive Locker podcast from Tec Clark have given me so much knowledge beyond just a standard divemaster course that I’d encourage anybody thinking of going pro to use every available tool to better themselves..
I will say the 6 footer we have take a little more practice to get enough air in them. I do have a question though. I’ve seen many videos reconnect not to pull on your line as it affects your buoyancy. That makes sense, but how do they get it to stand up vertically? I like your idea for the practice DSMB if the 6 footers didn’t cost so much. Maybe if you ran a short piece of cave line from the DSMB webbed harness to the overpressure reliefs valve lanyard you could dump the air simply by pulling down on your spool’s line during a drill.
I always just make myself very slightly negative once the DSMB is on the surface, then that little bit of weight on the line is enough to keep the buoy upright.
Reels usually, the locking mechanism gives you more chance of catching it if it falls. You can certainly use a spool with chunky gloves but you need to be a bit more careful and organised. Most cold water divers opt for reels.
Use a reel in cold water, I use Mcmahon large reel, for cold water, diving in cold lakes of Germany easy to use even with thick gloves, like everything practise makes perfect. Easy to send a DSMB up with.
