New setup weighting, check my math?

[feldomatic]

I was waiting on some money that finally came in and just bought my first full diving setup (certified in early April).

I kinda split both worlds and got a Backplate setup from DGX with an OMS wing, but then got an Aqualung legend regulator for local service reasons, and an i470TC because I wanted air integration under $1000 and figure by the time I outgrow it, Shearwater will release the Perdix 3 with AI powered decompresson algorithms or some such.

So while the BC ships, I'm doing the math to have a rough idea how much weight to rent this weekend at the quarry.

Here are my other weighting factors:

- 6'1" (185cm) 209#/95kg fairly broad framed, ~21% bodyfat by crude measurements
- 5lb stainless backplate
- 5mil wetsuit, hood, gloves and boots.
- Fresh water
- Last time I dove there I took 32lbs with a jacket bcd and a 1-2 year old 7mil.

I used This calculator and came up with 19 +/- 2 lbs. Seems light, but the shop at the quarry thought I was overweighted at 32lbs last time, I certified in the same place with 34#. Once upon a time a radiographer said I had big lungs (took 2 sheets of film to get them)

Assuming that 19lbs is a good starting point:

I know the backplate weight factors in, do I take the full weight off of that number?

In that case, I'm thinking 2lb in each of the trim pockets on my tank bands and the remaining 10# on my weight belt.

I also think I should rent about 25lbs just in case (it's like ten cents a pound to rent, so no biggie)

 

[lexvil]

I would have guessed 22lb, once the suit breaks in it will change, salt water it will change, every change to gear may lead to a change in weight requirements, it’s all just a starting point.

 

[VikingDives]

You were likely grossly overweighted. 19 pounds seems reasonable, but still too heavy.

Figure on subtracting 5 lbs for the BP/W. Try adding weight 2 lbs at at time until you can descend on exhale with an empty BP/W. At the end of your dive, dump your tank down to 500ish psi. See if you can descend again.

 

[inquis]

I'm the same height/weight and would use about 5 lbs of lead with that setup (assuming you're using an AL80 tank). Add 6 more lb for salt, given your build.

Generally:
1. Flood your suit.
2. Add weight to a handheld belt until you can descend with a full exhale and empty wing.
3. Add 5 more lbs of lead to what you needed in #2. (Again, assuming that used a full, single AL80 tank.)

 

[johndiver999]

start with 12 lbs on a belt

 

[Watthem]

Check out this thread & attached calculator sheet for a much more accurate idea of your requirements

Info - Optimal Buoyancy Computer

 

[feldomatic]

I wound up still floating with 16 on my preliminary weight check, bumped to 20 on the first dive and backed off to 18 for the rest of the day. I'm thinking I might not have done a good enough job emptying my wing on the first weight check because I still had a pretty fast descent rate.

Had an amazing day of diving on the new gear though. I thought I might have been too much of a gear snob being such a new diver and getting into a BPW and long hose setup, but no, they really are that awesome.

Now I just need to bungify this i470TC because that strap is NOT depth compensating.