Inflating DSMB from exhaled gas

[EireDiver606]

That sounds like a skills problem - why not just let go of the reel?

If you are deep, you only need like 5- 8 lbs of air when you release, so an initial mistake can probably be remedied by exhaling, dumping air from BC and hauling the thing back down? .

A skills problem to let go of reel? It’s never happened to me so I wouldn’t know. All I know is, spools normally and reels where spools cannot reach the surface.

 

[uncfnp]

A skills problem to let go of reel? It’s never happened to me so I wouldn’t know. All I know is, spools normally and reels where spools cannot reach the surface.

Sounds like a good plan...for you. For me, its always a reel.

 

[JohnnyC]

People lock off spools all the time. I lock off spools all the time, on those dives where I shoot a bag shallow enough to use a spool instead of a reel.

When you’re doing decompression stops, you don’t need the risk of losing the spool, it dropping, and now you have to deal with a spools worth of line trying to get all up in your business. You don’t need the hassle of trying to recover a spools length of line when you’re holding stops. You do this by locking off the spool, just like you lock off a reel.

Also, NOT all reels lock in place, in fact, only lockingreels do that without intervention. Most reels require you to manually lock them.

I’d like to know where you got the data backing up your assertion that “many” people are going for unintended ascents because they used a reel.

 

[KenGordon]

People lock off spools all the time. I lock off spools all the time, on those dives where I shoot a bag shallow enough to use a spool instead of a reel.

When you’re doing decompression stops, you don’t need the risk of losing the spool, it dropping, and now you have to deal with a spools worth of line trying to get all up in your business. You don’t need the hassle of trying to recover a spools length of line when you’re holding stops. You do this by locking off the spool, just like you lock off a reel.

Also, NOT all reels lock in place, in fact, only lockingreels do that without intervention. Most reels require you to manually lock them.

I’d like to know where you got the data backing up your assertion that “many” people are going for unintended ascents because they used a reel.

I think he means that reels can lock during the deployment.

Reels that need manual locking are really for line laying where you don’t want to be holding a lever down for ages. Reels for a DSMB only need to be unlocked for 30 seconds on the dive (maybe more on the ascent to avoid an annoying click). Self locking reels are what is commonly found in the U.K. where every diver has a DSMB on every dive.

Reels will typically have a loop on bungee to hold the bag in place before use. That can be used as a handle at a stop which helps reduce the effects of swell bouncing it up and down.

Everybody needs to experience screwing up a DSMB deployment to see how easy it is. Everybody should be prepared to let go. It takes three hands to do easily so having two divers help each other is advantageous.

 

[JohnnyC]

I think he means that reels can lock during the deployment.

Reels that need manual locking are really for line laying where you don’t want to be holding a lever down for ages. Reels for a DSMB only need to be unlocked for 30 seconds on the dive (maybe more on the ascent to avoid an annoying click). Self locking reels are what is commonly found in the U.K. where every diver has a DSMB on every dive.

Reels will typically have a loop on bungee to hold the bag in place before use. That can be used as a handle at a stop which helps reduce the effects of swell bouncing it up and down.

Everybody needs to experience screwing up a DSMB deployment to see how easy it is. Everybody should be prepared to let go. It takes three hands to do easily so having two divers help each other is advantageous.

You're making the same assumptions that he is, that not only the only reels people use for shooting DSMB's are the cheap click-lock style that you see in bargain bins, but that people are incapable of using such reels safely and without issue. I have never had a single issue shooting a DSMB from depth with any number of reels, no matter the style, from click-lock to sidewinder to the classic style like the Dive Rite's. Hundreds of DSMB's are deployed every day around the world with those reels without issue.

I am quite familiar with shooting DSMB's from a wide range of depths using a wide range of various line-dispensing apparatuses. You can just as easily screw up a deployment with a spool as with any style of reel. Both have advantages and disadvantages. Both are capable of sending you to the surface, both are capable of allowing you to more easily hold a decompression stop, both are easily deployed without issue world wide everyday. I realize that this doesn't fit the paradigm to which he has so thoroughly gone balls deep, but what can I say, I haven't taken fundies, I must be doing it wrong.

 

[Edward3c]

The nice thing about this technique is that the "system" (you & bag) buoyacy remains the same. Take as much time as you need to get the bag sorted out and initially inflated with just BC dump - you aren't getting dragged up. If you need more gas, the bag isn't flopping all over and a quick shot should do it. BC inflate & dump simultaneuosly to top off means you are already poised to start reestablishing bc-buoyancy and you can hang a little on the spool/reel to keep you in place.

I definately need to practice more to get smooth, but for me, it beats getting dragged up by a 40# bag.

To the OP, I’m not a fan of this method. With the DSMBs normally used in the U.K. transferring your buoyancy from a BC to the DSMB could leave you seriously negatively buoyant. I’m thinking 5 to 10kg, at depth without a bottom that could mean an increase in depth of at least 5m to correct. Completely screwing any deco plan. Additionally, most use drysuits for buoyancy.

This method might be okay in the tropics with one of the 3 or 4Lt bags.

My DSMB fully inflated has a capacity of around 14Lt = 14kg of lift.

 

[EireDiver606]

@JohnnyC @uncfnp and others I’m not saying reels are more dangerous to use but they DO have a locking feature, which if in high swells (Atlantic - here 1m+ at least) can pull you up at little bit and could cause you to violate your stop and sorry, but you’re not going to let go of a 50+£ reel if you ascend 1m + in the water column, and then come back down with the flow of the swells above you. It’s simply inconvenience. With a spool, you don’t lock it (at least I don’t), there’s no need to, you just hold it with one hand. When it pulls you up a little bit, you give it slack, to try to stay at the same depth.

I asked my GUE instructor in person why do we spools instead of reels, besides the fact that they’re smaller, cheaper, more simple. He said it wasn’t the reason, but one of them was “too many people have had runaway ascents with reels”. I think maybe he was referring to a legal issue, where people (who couldn’t let go of the reel) had runaway ascents and maybe this caused this. I’m speculating, I don’t know. Anyone know anything of this?

 

[EireDiver606]

When you’re doing decompression stops, you don’t need the risk of losing the spool, it dropping, and now you have to deal with a spools worth of line trying to get all up in your business. You don’t need the hassle of trying to recover a spools length of line when you’re holding stops. You do this by locking off the spool, just like you lock off a reel.

First of all, this is a basic scuba forum. So no, we’re not necessarily talking about decompression stops. I appreciate your insight into it though. Thank you.

Why would you need to lock off a spool? Just hold it. If you lose it, just cut it. When you’re ascending, no lock off is necessary.

 

[Edward3c]

@JohnnyC @uncfnp and others I’m not saying reels are more dangerous to use but they DO have a locking feature, which if in high swells (Atlantic - here 1m+ at least) can pull you up at little bit and could cause you to violate your stop and sorry, but you’re not going to let go of a 50+£ reel if you ascend 1m + in the water column, and then come back down with the flow of the swells above you. It’s simply inconvenience. With a spool, you don’t lock it (at least I don’t), there’s no need to, you just hold it with one hand. When it pulls you up a little bit, you give it slack, to try to stay at the same depth.

It’s not possible to hold a shallow stop in 1m swell without incurring at least +/-0.5m movement, when to let your line out your descending than ascending at the next trough; what’s that doing to your off-gassing.

When I’m doing a 6m stop I let the line run through my hand, or more commonly just ride beside it and watch it bounce up and down.

 

[Diving Dubai]

When I’m doing a 6m stop I let the line run through my hand, or more commonly just ride beside it and watch it bounce up and down.

Same as we do here.

I also do this with students, they find it easier to hold a stop with a visual reference like a locked off spool rather than eyes fixed on dive computer.

And totally agree with your point about swells too.