More weight to move from a 3mm Shorty to a 3/2 Full Wetsuit?

[JohnTRN]

I've been adjusting my weight down to get my gear 'dialed' in a little more.

In the past, with a jacket style BCD and my 3mm Shorty, I was using 16 lbs of weight. There's every chance this amount could have been reduced with some trial and error.

Last trip, with my new gear (Hydros Pro) and the 3mm Shorty, I got down to 12 lbs - 2 lbs in each trim pocket and 4 lbs in each dump pocket. That seemed to work very well. My lean bod was still getting chilled in 85F water! Mom said that getting old wasn't for sissies!

I've just gotten a 3/2 Full Wetsuit and wondering if I'm going to see a major, or minor, difference in weight requirements? I've tried some on-line calculators and there is both not enough input variables and tremendous output variables - anywhere from 6 to 9 to 16 lbs.

I've searched the 'Community' and the web and not come up with a very specific answer - short of getting in the water with full kit, and I'm not sure when I'll be able to do that again.

Thanks for any guidance.

John

 

[Raphus]

3/2 fullsuit should need more weigth then a 3 mil shorty. But since 12lbs is a lot for a 3mm shorty, i think you are just fine with the same amount of weigth.

If you have time before your next dive. Do a weigth check to get perfekt neutral bojant on the surface and add 4 lbs for the air. (or better: do the weigth check with an 700 psi/50bar tank)

 

[lowwall]

The difference will be 1 or 2 pounds, depending on how worn your old suit is. But, as Raphus pointed out, you are probably still overweight so it doesn't really matter.

If you can't do a formal weight check, you can dial it in over your dives. On the safety stop, get your bc completely empty and stop moving. If you sink, take a pound or two off for the next dive.

 

[boulderjohn]

I've just gotten a 3/2 Full Wetsuit and wondering if I'm going to see a major, or minor, difference in weight requirements? I've tried some on-line calculators and there is both not enough input variables and tremendous output variables - anywhere from 6 to 9 to 16 lbs.

I have experimented with several online weight calculators that I have seen recommended on ScubaBoard over the years, and I have never seen any come close. When I dived with a BCD similar to yours and a full 3mm suit in salt water, I needed 8 pounds. I will qualify that, though, by saying that I like being slightly overweighted, so I could have gotten by with less.

I just put my numbers from those days into online calculators, and here is what I got.

Divebuddy.com: 19 pounds
ScubaOtter: 10.4 (not bad)
Diveslist.com: 15 pounds
Divehot.com: 15 pounds

I have done the same thing over the years on these threads, and typically I get estimates about twice what I actually needed.

It is possible you need the weight you have been using, but I bet if I had a buoyancy session with you, you might change your mind. I once had a student come to me for his OW dives in a 7mm suit in freshwater. He told me he worked with an instructor in a pool with that 7mm suit and absolutely, positively knew he needed 22 pounds. When he finished the OW sessions with me, he was wearing 10 pounds and was oh-so-much happier about it all.

 

[JohnTRN]

Hi John,

Thanks for the reply.

I do need to sit and just experiment with weight requirements. More difficult to do right now, due to Covid. Just came back from Roatan and should have done a shore dive just to do that. Did drop down to 12 from 14 on the trip. Didn't want to drop more on one of the boat dives and then have to pause everything to grab some more weight. Did have some of the best buoyancy control control I've ever had - inhale/exhale to go up and down; minimal air in the BCD.

John

 

[JohnTRN]

Thanks for the replies Raphus and lowwall. Think I'll have to try starting out with my 12# and the new suit and see how it goes. Keep working on it. I'm tall, lean and rather floaty.

John

 

[Rickk]

Fill a bucket with water, (or tub or barrel or rinse tank or go to the pool or lake or ocean) put the suit in it and get any air bubbles out of it. Subjectively access how much force you need to put on it to make it sink.

Do the same with the other suit, compare the difference.

You can drop weights on top of suit to see just how much it takes to sink it. Use a mesh bag if you like to prevent the sleeves and legs from floating up on you. You can try on the suits and see how much weight you need to hold in your hand to get the same degree of flotation.

This is not rocket science folks, being a half kg one way or the other is not the end of the world.

Remember an average adult male has a range of lung inflation something like 4 litres (i.e. 4 kgs buoyancy) from fully exhausted to fully inhaled. The normal range is around 2 litres per breath so plus or minus a half kg is well within the range that you can adjust with your lung inflation.