As tech diver, diving single tank no-deco rec. in trim, what is your waist/hip lead?

[modustollens]

For a rec. dive with my BP/W I only have 2, 2lb weights attached at the back on the top cam band. I put them in this position for trim. I have not tried to ditch them or remove them underwater. My system is pretty balanced and I have had no trouble staying neutral throughout the entire dive. This is when I am in the tropics using only a thin wetsuit.

If I was to dive in Canada with a 8mm suit for the cold water I'd have to add my weight pouches on the harness at the waist or also use a weight belt.

 

[rivers]

If I'm in warm water, I don't need any lead. Cold water, 2 kgs on a belt and 2kgs on a cam band.

 

[Michael Guerrero]

I distribute weight between the upper and lower cam straps usually for warm water dives. If I'm in cold water I'm always in doubles and drysuit anyway, so then it's v weight and tail weight, none ditchable. If I had to wear my drysuit and go single tank, I'd put as much as I can on the cam bands and the rest on a belt, but just because that's what I have, not because I want to ditch it.

 

[rsingler]

With my 6lb. steel backplate, I don't need weight wearing a wetsuit or drysuit using single or double aluminum cylinders.

I'm having trouble deciding if you're being facetious. "Wearing a wetsuit or drysuit..."
A 5mil has about 16# buoyancy
A drysuit that's not compressed flat against your skin (eliminating its insulation) may have 12-30# buoyancy (or more).
A single aluminum 80 is +4# at 500psi
Doubles Al might be about the same counting the manifold.
I could see at depth with a compressed wetsuit, a guy with minimal body fat and a full 80 might be neutral with a 6# plate.
But end of dive at 15ft in either 5 mil or drysuit, I can't make the math work.

Are you teasing us? Making sure someone is paying attention?

 

[Trace Malinowski]

I'm having trouble deciding if you're being facetious. "Wearing a wetsuit or drysuit..."
A 5mil has about 16# buoyancy
A drysuit that's not compressed flat against your skin (eliminating its insulation) may have 12-30# buoyancy (or more).
A single aluminum 80 is +4# at 500psi
Doubles Al might be about the same counting the manifold.
I could see at depth with a compressed wetsuit, a guy with minimal body fat and a full 80 might be neutral with a 6# plate.
But end of dive at 15ft in either 5 mil or drysuit, I can't make the math work.

Are you teasing us? Making sure someone is paying attention?

No. I packed on some decent muscle over the years. I started running barefoot in martial arts in high school. Doug Mudry once told about Wolff's Law and that years of heavy exercise may have created denser bones.

In 1999, while working as a scuba instructor in the Caymans, I was struck by a car that the driver said was traveling at 40 - 50 m.p.h. while I was standing on the road as a pedestrian. The car was totaled. I didn't have a single fracture. X-rays and bone scans showed there wasn't even a hairline fracture. The doctors, nurses, EMT's, and myself put my survival down to: 1) God 2) A diet of milk & yogurt 3) Exercise. Back in high school, a guy punched me and broke 5 bones in his hand. He hit me in the back, but @The Chairman could tell you my jaw probably gets enough exercise where he could have done the same with a punch to the face.

At age 50, I do run - swim - runs at the beach to maintain USLA fitness standards. Lift heavy following a 5 x 5 strength training program and do 1 - 2 mile runs, swims, and sets of 5 x 200's, 5 x 100's, 5 x 50's sand sprints. Still plugging away. I don't need a weightbelt to freedive either.

 

[rjack321]

As a cold blooded cold water 49yo diver with a history of dcs (and generally feeling crappy after some dives) I found the choices laughable. I have a crushed neoprene suit and weezles fluffiest undergarment. Thus, in a single steel hp100, if you combine the BP, STA, lead on the cam bands, and lead on my waist I have a ton of lead to sink that and puff it up to stay warm and offgas while basically floating in 46 to 55F water (depending on the season here). 38lbs actually. Making that "all ditchable" is not gonna happen, neither is "none ditchable". Without having it in front of me I think about 16lbs is integrated and 22lbs is ditchable.

 

[Compressor]

If you're trained as a technical diver, when you dive recreational and in trim, how much of your removable and ditchable lead is in the waist or weight belt zone, so potentially ditchable if you wanted?

Canonically with vacation diver AL 80, but whatever you actually use, single tank no-deco, is fine. The intent is that your tank choice leaves you with some leeway in ballast placement, if you choose to use it. Ditchable means quickly ditchable by you with the BC still on. So, for back mount, it mostly means BC waist belt integrated or weight belt.

With the presumption that your weight is likely split between some typically non ditchable locations (plate, BC trim pockets, shoulder weights, back mount tank straps, etc.) while some might be in locations that are both lower and typically support ditching (mostly likely in ditchable waist pocket or weight belt).

There is a current thread "Question about “balanced rigs” and having all ballast unditchable". It seemed some data would be interesting about how those likely ingrained with a strong definition of in trim distribute weight recreationally.

A good number of tech might prefer side mount, so I stretched the single tank rec definition to include small side mount as well.... But not so big that you're neutral or negative with just your gear.

The poll results are fascinating. At this time 61% are non-ditchable. WOW I got to read the comments carefully.

 

[rsingler]

Maybe this is the time to comment about a tool under development...
For those of you interested in the details, or who carry negatively buoyant rigs due to the amount of gas you carry, or other considerations, we are developing a spreadsheet that will quantify the issues:
How negative am I when my wetsuit is compressed at depth?
If I have ditchable weight, how much can i shed in an emergency (torn wing, flooded drysuit) and not have a runaway ascent?
If I have nothing to ditch, how much am I swimming up?
How much redundant lift is enough?
And other questions...

An initial effort (well, actually the eleventh effort) can be found at
Help with wing lift calculation
But this is in need of significant improvement, and several of us are collaborating. I'll report out both here and there when the next iteration is published. In the pending release, we have many more tanks entered, if you don't know your tank buoyancy. We are also trying to develop several side-by-side comparisons for those of you that want to get down in the details. It began with the question, "How big a wing do I need?" , a question which has been asked on this forum many times.
And from there, it's begun to morph.
Stand by for more features, some of which should address the math of whether or not, and how much, of your weight should be ditchable.

Cheers!
Here's to balanced rigs!...when you can have them...

 

[Michael Guerrero]

I dive weighted to try and be neutral with all my tanks (doubles, stages, deco) near or at empty. That way I should be able to hold a shallow stop on my last bottle of breathing gas. I have redundant buoyancy for wing or suit issues.

 

[KentB]

With my 6lb. steel backplate, I don't need weight wearing a wetsuit or drysuit using single or double aluminum cylinders.

jesus i cant fathom that
Im not doubting you but my fat ass in drysuit needs 30# and a steel tank i usually dive with 32# just so i can have enough air in drysuit @ SS Im not getting squeezed. at 30 # i have a hard time holding a stop
this is total weight including BP and STA not including tank.
everyone seems to say with more experience you can drop usually drop weight but I dont know. Im a floater, swimming i can breathe completely out and I still dont sink