Question about “balanced rigs” and having all ballast unditchable

[Storker]

You're still completely missing or - more likely - ignoring the fact that much of the discussion lately has been about ditching at the surface.

 

[MichaelMc]

MichaelRyanSd,

Diving a 7mm suit influences how much lead you need. It does not force a choice to put that lead into the plate, if that lead is still say less than 15lb or in your case ~10. That is easily handled by weight belt, pockets designed as ditchable, and trim pockets. It might be convenient to use a steel plate, but it is not a forced choice. If it is 20+ lb., it is likely silly to not put some permanently in the plate.

But if putting lead in the plate in the form of steel leaves you with too little to juggle between trim and surface ditchable for waves, lost, exhaustion, etc. then go with a lighter AL plate, so you have more control over where that lead goes. Whether tech divers dive negative/no ditchable because they have no choice for how much air they carry, is not a factor for rec. diving when you still have a choice. And instructors and guides have reasons, saving wayward students, for diving a bit negative, put they are pros.

 

[Dan_P]

You're still completely missing or - more likely - ignoring the fact that much of the discussion lately has been about ditching at the surface.

That's because I think a solution that works well in one specific place (and imposes a host of problems elsewhere) is still an inferior solution to another one that works just as well or better in that place (and doesn't impose a host of problems elsewhere).

 

[CT-Rich]

That's because I think a solution that works well in one specific place (and imposes a host of problems elsewhere) is still an inferior solution to another one that works just as well or better in that place (and doesn't impose a host of problems elsewhere).

I think you have it backwards, you’re very narrow solution seems to be what you think everyone should do, but in reality the general solution of ditch able weights works for most recreational diving. Your idea of having a “balanced rig” is based on the presumption that everybody will dive exactly as you do.

Ditchable weight creates redundant buoyancy

 

[Bob DBF]

Is with people thinking that this is about parachuting up from the bottom of the ocean?

The only way you will parachute up from the bottom is if you have air in your BC, which will make dropping weight unnessary. I use a 7mm farmer John and if I was at 60' with an empty BC I can drop my substantial weight belt and not go anywhere. It would make kicking up easier, and at some point around 40' I would start being noticeably being positively buoyant. By kicking down or spreading out horosontal I can slow my ascent to something reasonable. No drama, no ballistic launch.

I don't know why anyone would drop their belt at depth with a functioning BC holding them neutral and then, on top of that, not dumping the BC on ascent.

@Eric Sedletzky pointed this out earlier. I guess dropping the freediving portion of OW should be revisited, as it is easier to experience and understand buoyancy without a BC, or may be it is just me.



Bob

 

[Eric Sedletzky]

Ditchable weight creates redundant buoyancy

^^this^^ should be the quote of the century.

@Dan_P, this is the basic forum. We are not concerned about what tech divers or cave divers do. This thread was created to ask the question of how non ditchable lead leaked into standard recreational diving and if such a practice is really that good of an idea when presented to new divers who may not have a handle of what properly weighted means yet.

 

[Bob DBF]

This thread was created to ask the question of how non ditchable lead leaked into standard recreational diving...

Emulating the big kids. If you look like a proffessional, the people will think you are one. A basic technique used to sell gear like the instructor wears to new divers. When the new diver takes tech divers as their heroes, they buy tech gear and set themselves up like tech divers.

...and if such a practice is really that good of an idea when presented to new divers who may not have a handle of what properly weighted means yet.

I don't think it is a good idea for any diver, new or old, to start using a rig without understanding why it is set up the way it is, and whether it is the proper rig for the their diving. This should start with proper weighting and the safety procedures and gear needed to conduct their dives.

OW training includes the use of ditchable weight in order to respond to an emergency, and without further training,formal or informal, to discuss how to mitigate not having ditchable weight, the diver looses an emergency procedure without an alternative.



Bob

 

[Eric Sedletzky]

I’m going to go out on a limb and say that better than 50% of newly trained divers trained by all basic OW agencies are diving overweighted.
It simply has become a standard practice to add several more lbs (or kilos) to make sure students can get down. The problem is they never rectify this practice once the student moves on, and the new diver then thinks this is how they must be weighted. If they take that amount of weight they were trained with and convert it all to non ditchable ballast then they are really up sh!t creek if something happens. Very very bad advice, right behind the bigger issue of being grossly overweighted from the start and thinking it’s normal.
This is why you hear about divers in distress coming to the surface only to descend again to their deaths.

 

[Diving Dubai]

This is why you hear about divers in distress coming to the surface only to descend again to their deaths

Often, all too often, divers having a "flap" at the surface forget to inflate their BCD. If in a moment of panic they can't do this, then why should their brain tell them to ditch weight? Even though people are taught all of the above in theri training, in a moment of panic, some forget. If you're OOA of course then ditching weight is your only option to get positive buoyancy.

While it's true, newer divers are given excess weight at in training to assist them while nervous. Divers do see weight as their comfort blanket. try to persuade a diver that they need less weight and often it'd be easier to take money out of their wallet then take weight of their belt. This applies to experienced divers also

Lots of divers fail to realise that excess weight exacerbates bad buoyancy, they fail to grasp that the additional air needed in the BCD to compensate for the excess weight will have a greater effect when it expands. They think this is due to being underweight and add more weight . A vicious circle.

On the PPB course (which is my favourite to teach) I sive up the student and left them start with their weight choice. I have a good idea what they will really need, and then have a friendly bet with them.

I spend an inordinate amount of time on buoyancy checks to get them dialled in. I have a full selection of weight sizes down to the 1lb (0.5kg)

Once we've reduced the weight to what they actually need and go through the exercises - a common fear is that they'll be light at the end of the dive. I disprove this by purging their tanks down to 30 bar (400psi) and getting them to hold a stop at the end of each dive.

For all its a revelation having been properly neutral for the first time and certainly generally having never had so little lead on their rigs.

 

[Tom_Ivan]

Why are people talking about OOG situations in this thread? You would have been neutral (or close to) before you ran out of air so as soon as you ascend you become positive. No reason to drop any weight in an OOG emergency. This is covered in the basic PADI course and is why we don't get taught to ditch weights during a CESA. If need be then orally inflate your BCD further when you are on the surface.

If people wan't to discuss dropping weights to counter a blown BCD then I can follow the logic but not OOG.