Error Local diver critical - Cirkewwa harbor, Malta

[Tritip]

If it is 11KG can a fully inflated BCD overcome it to make it buoyant?

 

[DandyDon]

If it is 11KG can a fully inflated BCD overcome it to make it buoyant?

11 Kg = 24.2508 pounds. Depends on the BC. Mine has 40# of lift, but some have "travel BCs" with much less.

 

[Ukmc]

You are correct. You should always test your gas supply before entering.

You are not correct. I’ll bet my twins (steel HP hundreds) are -20 lbs (10 ish kilos) full add a stainless backplate for another 4 lbs.

I am not sure I understand you. What I am saying is if your rig is SO negative diving- jump in at least with a half inflated BCD. If you half inflate your BCD prior to jumping in, you will know your gas is off before you take a plunge.
This is much negativity (no pun intended) is foreign to me, as I dive a single tank warm water balanced rig to the point that most of the dives I don’t need to put much air if any at all.

 

[Wookie]

I am not sure I understand you. What I am saying is if your rig is SO negative diving- jump in at least with a half inflated BCD. If you half inflate your BCD prior to jumping in, you will know your gas is off before you take a plunge.

You are correct. You should always test your gas supply before entering. Having an inflated wing is a great idea.

This is much negativity (no pun intended) is foreign to me, as I dive a single tank warm water balanced rig to the point that most of the dives I don’t need to put much air if any at all.

Well, when you get tech certified in cold water diving twin steels, you will see how much negative they are.

My doubles wing is 65 lbs of lift, which is enough.

 

[Kay Dee]

I don’t dive doubles, but there are several things I don’t understand - one test your BC and breathe from the regulator prior to entry . Two - Iit dumbfounds me that one would be so negative diving on a first place that they can not find up and even more so do not inflate BC prior to jumping in (even for negative entry). Something doesn’t match up here. I guess we don’t have a lot of details to go by.

What @Wookie said and...........

1) Be dumbfounded. Depending on the type of doubles, steel or aluminium, you are using and the rest of your 'tech' kit, one can be very negatively bouyant.

2) The are many instances in both rec and tech in the ocean where you want to jump / go in with an empty bc. You are may be thinking in strictly recreational terms where after going in (from a boat say) you want to stay on the surface (and give the ok signal to the boat, etc). Often in tech (from boat or shore) you want to get off the surface and down quickly, sometimes very quickly, so jumping / going in with a deflated bc / wing is necessary / common, or was in my neck of the woods (and I did it habitually, unless with students, and even then sometimes, depending on the conditions / 'type' of student/s). And then not inflating it until you are nearing / almost at the bottom is also common in some areas / circumstances (i.e. wreck diving in strong currents, say for example south Florida at times).

Same goes for @Tritip, you are thinking it seems in strictly 'recreational' diving terms / scenarios. And although tech divers dive for recreation it is far from recreational diving, if you get my drift (no pun intended). However, re your previous 'answer' to the question I posed, if your memory is so bad that you cant remember what you were taught / practiced then I hope for your sake that you are not still diving.

 

[Edward3c]

If it is 11KG can a fully inflated BCD overcome it to make it buoyant?

Do you know the lift capability of your buoyancy device, mine is 25kg, but some travel ones are as low as 8kg (leave a litre of water in one and you’ve lost a kg.)

 

[Ukmc]

What @Wookie said and...........

1) Be dumbfounded. Depending on the type of doubles, steel or aluminium, you are using and the rest of your 'tech' kit, one can be very negatively bouyant.

2) The are many instances in both rec and tech in the ocean where you want to jump / go in with an empty bc. You are may be thinking in strictly recreational terms where after going in (from a boat say) you want to stay on the surface (and give the ok signal to the boat, etc). Often in tech (from boat or shore) you want to get off the surface and down quickly, sometimes very quickly, so jumping / going in with a deflated bc / wing is necessary / common, or was in my neck of the woods (and I did it habitually, unless with students, and even then sometimes, depending on the conditions / 'type' of student/s). And then not inflating it until you are nearing / almost at the bottom is also common in some areas / circumstances (i.e. wreck diving in strong currents, say for example south Florida at times).

Same goes for @Tritip, you are thinking it seems in strictly 'recreational' diving terms / scenarios. And although tech divers dive for recreation it is far from recreational diving, if you get my drift (no pun intended). However, re your previous 'answer' to the question I posed, if your memory is so bad that you cant remember what you were taught / practiced then I hope for your sake that you are not still diving.

I understand that with the diving you and @Wookie are doing, you may have to be 20-30 pounds negative (although it still sounds crazy but I get it) and I also understand the need for negative entry. This is not what I am questioning. 5-6 lbs of negative buoyancy and I drop like a rock. Why would you ever need to be 25-30 lbs negative for the entry??? I know you can not help your rig being too dense (or can you?), but I would think you would want to have your BCD inflated to some degree to still keep you negative but not 25 lbs negative. And even if one was not trained to test your BC inflator prior to entry (I would think technical diver would just like recreational divers), then you still would catch it that your valves are not open as you try to make yourself less negative prior to jumping in.
I also understand that it is a Swiss cheese for many accidents - check your valve open, test your air prior to jumping, test your BC open, do your valve drills , have your buddy check you if you are not solo etc… And any one intervention may have averted the accident. I just have a hard time wrapping my head around how this happened and wondering if something else was at play.

 

[Edward3c]

I understand that with the diving you and @Wookie are doing, you may have to be 20-30 pounds negative (although it still sounds crazy but I get it) and I also understand the need for negative entry. This is not what I am questioning. 5-6 lbs of negative buoyancy and I drop like a rock. Why would you ever need to be 25-30 lbs negative for the entry??? I know you can not help your rig being too dense (or can you?), but I would think you would want to have your BCD inflated to some degree to still keep you negative but not 25 lbs negative. And even if one was not trained to test your BC inflator prior to entry (I would think technical diver would just like recreational divers), then you still would catch it that your valves are not open as you try to make yourself less negative prior to jumping in.
I also understand that it is a Swiss cheese for many accidents - check your valve open, test your air prior to jumping, test your BC open, do your valve drills , have your buddy check you if you are not solo etc… And any one intervention may have averted the accident. I just have a hard time wrapping my head around how this happened and wondering if something else was at play.

What we don’t know is whether there was a distraction during his pre-dive routine. I’ve entered the water without fins when distracted. Now if distracted I’d like to think I would start the routine over, but we’re all fallible.

 

[Kay Dee]

Mine in red below.

I understand that with the diving you and @Wookie are doing, you may have to be 20-30 pounds negative (although it still sounds crazy but I get it) and I also understand the need for negative entry. This is not what I am questioning. 5-6 lbs of negative buoyancy and I drop like a rock. Why would you ever need to be 25-30 lbs negative for the entry???
You don't need to be, you sometimes just are. Depending on your gear, say DPV, double steels or a CCR, a stage bottle or two/three, a camera rig or two, etc.) sometime you just are heavy, by a considerable degree. But did I miss something, where does it say he was that 25-30lb's negative?

I know you can not help your rig being too dense (or can you?),
You can trim down what you carry up to a point, but still you will / may be negative, and maybe be quite a bit. Also why a lot of folks like to dive with ally cylinders, which was the exact reason I didn't (too light).

but I would think you would want to have your BCD inflated to some degree to still keep you negative but not 25 lbs negative. And even if one was not trained to test your BC inflator prior to entry (I would think technical diver would just like recreational divers), then you still would catch it that your valves are not open as you try to make yourself less negative prior to jumping in.
Trained to do so doesn’t always equate to actually doing so, unfortunately.

I also understand that it is a Swiss cheese for many accidents - check your valve open, test your air prior to jumping, test your BC open, do your valve drills , have your buddy check you if you are not solo etc… And any one intervention may have averted the accident. I just have a hard time wrapping my head around how this happened and wondering if something else was at play.
Methinks you are just over-analysing it. On the surface of it (no pun intended) and until / if we learn more, given the 'circumstances' it looks relatively straight forward after the fact - i.e. after going in - to me (the accident that is).

 

[Wookie]

Yes. I’ve forgotten fins once. Once only. As captain of the boat it was tough to overcome.

In the USA, jumping negative is called a lawn dart. A game from the 80’s where a player threw a heavy piece of sharp steel at a ring on the ground and the dart had to stick in the bottom. Anyway, jumping on certain deep wrecks in the Florida Keys and many other places means jumping as heavy as possible and getting to the wreck as soon as possible so you can see and find the wreck. The captain will put you in up current, but there is no time for OK signals on the surface, and if you did, the next diver is likely to jump on your head. Think penguins all jumping off the iceberg.

So you all don’t think we’re just crazy, I will be in Belize next week, diving single 80 aluminum recreational profiles. I will wear my backplate and singles recreational wing, with 5 kg of lift, no wetsuit, no drysuit, a single regulator with long hose and an Air2, because I’m ornery. And it’s never failed me. But when it does, it will probably kill me.