Proper weighting with doubles.

[TSandM]

I don't think Tobin's weight plates work with doubles, though . . . they bolt onto the back of the plate, and the bolts won't reach. I'm pretty sure Peter found that out.

V-weights, heavy plates (Fred T makes one) and weight belts or harnesses are the solutions I'm used to seeing. I dive my 85s with either my Al plate and a 6 lb v-weight or a SS plate, and 16 lbs on a belt.

 

[rjack321]

I have an obscene amount of lead on me in doubles. But weezles take alot of gas which is (duh) why I'm actually warm after ~80-90 mins in <50F water.

I carry between 18 and 23lbs on a belt with steel doubles - I have 85s, 95s, 119s and 108s the 85s and 108s are a little lighter than the 95s and 119s. On top of a 6lb plate. I can move some of that lead to an 8lb tailweight I made, or a DDS tailweight pouch. Doesn't really matter much as long as the lead's "low-ish" on the tanks.

One thing I won't use is any kind of velcro weight holders, they aren't reliable enough for tech diving IMO. Ditto plastic belt buckles, use a robust stainless one.

I'm weighted for empty doubles and one empty AL80. The AL40s don't really become positive with a reg on them so I don't worry about those, I could always run the suit a little bit more compressed if I were in a bind.

 

[TSandM]

23lbs on a belt with steel doubles

That's obscene, all right! Yikes!

 

[Paladin]

I use 8 to 10 pounds with my 3mm wetsuit, horsecollar BC and twin steel 72s. This makes me a little heavy at the beginning of the dive and just slightly negative or neutral at the end. My backpack is one of the old plastic Healthways Campacs that I converted to doubles.

This is in freshwater. Saltwater would require another 5 pounds or so.

 

[kanonfodr]

This may be a bit of a silly question, but I have been getting some different answers and was curious what other think about this question.

After doing some experimenting, I have determined that my exposure suit makes me 34lbs positively buoyant.

My doubles kit is 35lbs negative when full. the tanks are LP120's which hold 20lbs of air.

So that means i am negatively buoyant at the start of my dive but am 19lbs positive at the end.

As it sits, the kit had very good trim and I have no problems in that department. I am mostly concerned about the weighting.

I have been told various things about the weight required to compensate for the variable weight of the air. How much weight would you add to compensate for the backgas? and where?

To put it simply, you weight yourself with your tanks empty (about 500 psi) at your last stop (10-20 feet), with your wing empty and drysuit empty. Pick a number, throw that onto a weight belt, and check it by stopping at your last stop depth, then deflating everything. If you sink a little bit, take off two pounds. If you sink a lot, take off more. If you float a little bit, add 2 pounds. If you float a lot, add more. If you're neutral, keep it there. Friends help.

FWIW, I weight myself a pound or two heavy @ 500 psi, that way if I gotta stretch my tank a bit I can. Gentle sink on the exhale, SLOW ascent on inhale. Puff of air to get neutral.

Peace,
Greg

 

[limeyx]

I don't think Tobin's weight plates work with doubles, though . . . they bolt onto the back of the plate, and the bolts won't reach. I'm pretty sure Peter found that out.

It is possible to mount Tobins weight plates onto the front of the plate. I dont know for sure if that makes them work with doubles but they do work with the MC90

 

[rjack321]

That's obscene, all right! Yikes!

Being cold sux. Potentially blowing deco is worse.

Wearing less weight does not magically make one's buoyancy better. Being overweighted is not desirable, but there seems to be an internet obsession with dropping as much lead as possible. To the point where people are actually significantly underweighted in doubles because they aren't running the tanks down very far so they don't realize what's going to happen when they dip into some of that redundancy and actually lose or use some of all that gas.

 

[garyd54220]

Pinnacle EVO 2 drysuit with Weezle's underneath. Either double HP steel 100's or 120's (doesn't matter, same either way) with 6lb plate. One 40 for oxygen. Cold fresh water (Great Lakes). No additional weight. With the KISS I have a 6lb cap weight for both trim and weight although it could probably be lighter.

 

[TSandM]

Oh, Richard, I'm not at all for diving underweighted, and in fact, I've said many times that i deliberately overweight myself by a couple of pounds to stay warmer and make hanging onto a bag easier. I just thought I dove with the most weight of anybody around here, and you have me beat!

 

[String]

MY subxero is about 4kg (9lbs) more positive than a weezle extreme. i need a LOT of lead to stay down on that even in a steel twinset!