My wife won't sink

[Rose Robinson]

What does "sets her neutral buoyancy pre dive" mean?

Neutral at the start means 4-5 pounds light once you breathe down your gas. Good luck holding a safety stop.

And "no lead ballast" with a single tank and a 7mm suit? You could maybe get there with stainless steel in the form of a really thick backplate and a big steel HP tank, but that's not relevant to this situation.

Achieving neutral buoyancy, predive, is one of the most important things a diver can do, and one of the most important things we all are taught during our OW scuba course.

Of course she's going to need ballast, which is determined predive, while achieving neutral buoyancy.

Intentionally entering the water negative, for the sake of initial submersion, never has and never will be a good idea, nor is it a safe diving practice especially for a beginner, because, as you start to sink, the first thing that comes into your mind is putting air in your BC, which could lead to an uncontrolled ascent, which at depth can be an extreme safety hazard.

Further, if you start your dive, having set your neutral buoyancy, and follow the rule of thirds, holding a safety stop, even if you are not holding onto the shot line, is not an issue.

I never touch the shot line during an ascent, that's what staying neutral at any depth is al about.

I was told many years ago that scuba diving is 90% peak performance buoyancy, and 10% everything else. It's not quite that, but not far off the mark.

I have never forgot an Atlantic charter I was on in the early 2000's, There was a diver on our boat, maybe 5' 8''/5' 9'', 200 pounds, diving with a drysuit, double HP 130's, and 40 pounds of lead. I couldn't believe what I was looking at.

A lot of his problem had to do with his drysuit, as there was enough room for him and two small elephants, all the creases/folds/overlapping in his suit was trapping lots of air. Diving safely, I think not.

Rose

 

[Rose Robinson]

This is unhelpful, completely. If she was neutral negating the suit there would not be a problem.

You cannot dive in cold water with a drysuit (BC right?) without weights unless you are using gigantic steel negative doubles or the like. It's not at all relevant to the situation.

Hi Dave,

Sure it is, read my post 51.

The suit has to be in the equation, she can't very well dive in the nude.

Achieving neutral buoyancy pre dive makes absolutely no difference what you are wearing for kit or exposure protection.

Neutral on the surface or at any depth is neutral, the same as saying one is one.

I can be neutral in the Atlantic with my bathing suit and coveralls on, diving the U352, just the same as I can be neutral in the North Pacific, diving off the cost of BC in my shorts/top/undergarment/drysuit, in both cases, HP steel 80's, aluminum BP, and no ballast. As I mentioned in a previous post, I own no lead ballast, I never have, and I've been diving a long time, around the world and back.

Diving is not about lead. It's about learning peak performance buoyancy. Why dive with an aluminum 80, and 20 pounds of ballast, when you can dive a hp steel 100, and no ballast.

Most if not all dive destinations have steel cylinders and I make sure the local dive shop has steel cylinders as part of my trip planning.

I've even taken bands/bolts/manifold with me, so I can put a set of doubles together upon my arrival. Only once did I ever bring the bands/bolts manifold back. In all other cases, the destination dive operator was more than happy to buy them from me.

Regards,

Rose.

 

[tursiops]

Diving is not about lead. It's about learning peak performance buoyancy. Why dive with an aluminum 80, and 20 pounds of ballast, when you can dive a hp steel 100, and no ballast.

You seem to be suggesting that a HP100 steel weighs 20 pounds in the water. Really?

Most if not all dive destinations have steel cylinders and I make sure the local dive shop has steel cylinders as part of my trip planning.

Most of the Caribbean and LOB destinations I have gone to (dozens?) do NOT have steel cylinders available.

I've even taken bands/bolts/manifold with me, so I can put a set of doubles together upon my arrival. Only once did I ever bring the bands/bolts manifold back. In all other cases, the destination dive operator was more than happy to buy them from me.

The boat diving i've done on travel (both LOB and from resorts) do NOT usually allow twins...they typically support recreational diving only, with seat space for a single tank. Perhaps you are talking about tech charters?

 

[lowwall]

Achieving neutral buoyancy, predive, is one of the most important things a diver can do, and one of the most important things we all are taught during our OW scuba course.

Of course she's going to need ballast, which is determined predive, while achieving neutral buoyancy.

Intentionally entering the water negative, for the sake of initial submersion, never has and never will be a good idea, nor is it a safe diving practice especially for a beginner, because, as you start to sink, the first thing that comes into your mind is putting air in your BC, which could lead to an uncontrolled ascent, which at depth can be an extreme safety hazard.

Further, if you start your dive, having set your neutral buoyancy, and follow the rule of thirds, holding a safety stop, even if you are not holding onto the shot line, is not an issue.

I never touch the shot line during an ascent, that's what staying neutral at any depth is al about.

I was told many years ago that scuba diving is 90% peak performance buoyancy, and 10% everything else. It's not quite that, but not far off the mark.

I have never forgot an Atlantic charter I was on in the early 2000's, There was a diver on our boat, maybe 5' 8''/5' 9'', 200 pounds, diving with a drysuit, double HP 130's, and 40 pounds of lead. I couldn't believe what I was looking at.

A lot of his problem had to do with his drysuit, as there was enough room for him and two small elephants, all the creases/folds/overlapping in his suit was trapping lots of air. Diving safely, I think not.

Rose

There appears to be a communication failure here. We are talking about how to submerge from the surface. Entering the water negative has never been suggested by anyone on this thread.

When you are on the surface, you have two options to get under. You can make yourself negative and let gravity do the work or you can swim down. We are mostly offering suggestions for getting negative without adding weight such as exhaling or minimizing trapped air. There have been a few suggestions to swim down a bit because it's a 7mm suit and the buoyancy swing is very noticeable in the first 5-10 feet.

 

[grantmac]

I have no idea, I'm just throwing BS out there. I do need 30 with my 100 though for my own comfort.

I need perhaps 20# with a single steel so there you go. What's weird is in theory my doubles are only 10# heavier in water.

 

[Rose Robinson]

There appears to be a communication failure here. We are talking about how to submerge from the surface. Entering the water negative has never been suggested by anyone on this thread.

When you are on the surface, you have two options to get under. You can make yourself negative and let gravity do the work or you can swim down. We are mostly offering suggestions for getting negative without adding weight such as exhaling or minimizing trapped air. There have been a few suggestions to swim down a bit because it's a 7mm suit and the buoyancy swing is very noticeable in the first 5-10 feet.

You don't get negative, you get neutral!

You become negative enough as you descend down through the water column.

As far as the 7mm suit and the first 5-10 feet, that's why you start of neutral.

Rose.

 

[Rose Robinson]

You seem to be suggesting that a HP100 steel weighs 20 pounds in the water. Really?

Most of the Caribbean and LOB destinations I have gone to (dozens?) do NOT have steel cylinders available.

The boat diving i've done on travel (both LOB and from resorts) do NOT usually allow twins...they typically support recreational diving only, with seat space for a single tank. Perhaps you are talking about tech charters?

Not at all, but they are negative, not positive, and starting off neutral is easier to achieve if you don't have to start off loading up with ballast to achieve neutral buoyancy. You may still need ballast, but nowhere near as much.

As far as what destination charter operators allow or don't allow, or whether or not they have steel tanks is what prior planning is all about.

You don't show up at the hotel with no prior planning, why show up at the dive operators with no prior planning. My charters and any needed requirements are all pre booked, same as hotel, transportation and everything else that needs to be planned for ahead of destination arrival.

Rose

 

[Rose Robinson]

I have no idea, I'm just throwing BS out there. I do need 30 with my 100 though for my own comfort.

BG,

I dive with a drysuit full time, 80 cu. ft HP steel doubles, no ballast whatsoever.

I have no idea of your size and weight, but I guarantee you, if you were to spend an afternoon with me, I could help you drop 10 pounds off that number, probably more.

From what you are saying, you are likely using the better part of your fill to constantly inflate and deflate your wing, to stay neutral at depth.

I dive a lot of locations where the bottom may be 1000's of feet down. being able to stay neutral at your chosen depth, means your life.

Rose

 

[Boarderguy]

From what you are saying, you are likely using the better part of your fill to constantly inflate and deflate your wing, to stay neutral at depth.

1) most of my dives are sub 90 fsw and they extend to 1 hour + on HP 100s. My air consumption is through my lungs, not my suit.
2) I'm 3-4lbs heavy. With an uncomfortable squeeze and empty wing at 20 I struggle to stay down without those lbs. At 10 it is nearly impossible. I use those so I can stay a bit puffed throughout the dive and be comfortable while on my short 20 min deco hangs.
3) I've worked to reduce my weights and found my happy point to be comfortable for me style of dives in my cold water backyard. No need to be absolutely minimalist in weight when you have multiple forms of buoyancy and being cold is a risk to DCS.

I'm glad you can go null weight with twin 80s, when I put together my twin 100s later this year I'll drop a good bit of what I use, but will maintain enough to hold my stops without concern while staying warm.