Drysuit weight question

[Kronek]

Hey guys, I just picked up a Bare D6 drysuit. Right now I am wearing 45lb of lead with a 7mm farmer john/top, but I know I am way over weighted, just keep forgetting to take lead off my belt.


How much weight do you think I could drop with the drysuit? I am going out tonight with a DM to get the hang of it, but I'm sitting at work wondering and I want to at least have a ball park for the weight.

I am 6'3, 250lb with AL80 tanks fyi.

I tried searching for this, but couldn't find anything, then skimmed the last 5 pages. If there is some super thread, please point me at it

 

[NAM001]

KRONIC

THERE IS BUT ONE SIMPLE WAY TO quickly DO THIS. Get into a pool with only the bare 7m. then repeat with the dry suit. ecach time determind what weight you need to stay down. the differnce is what you wil need to add or sub from the belt.. 45 seams to be a lot however your size and mine is comparable and my 3 mm farmer john needs 19# so that number may be close for the 7mm. i would think you should be at perhaps 25-30 with the dry suit since the 7mm is close to the 3mm farmer ( double 3mm layer)

 

[Jerry_]

With a drysuit you will need extra weight, than with a wetsuit.

However, as you point out that you are overweighted, when using the wetsuit, it might be fine for the drysuit.

As regards the weight (45lb) I would defintely start finding out what your correct weighting should be, but not when starting to use new equipment.

The way to find out the correct weighting is to check the weight you need for correct buoyancy at the end of a dive (i.e when the volume of gas in the tanks is to what t would be at the end of a regilar dive) at the level of the last deco stop (3m). For doing so, trim your weight almost fine and place some weights in pockets during the dive. Then at the end start removing them one by one.

Getting back to the initial question: prepare to take some extra weight to be placed in pockets, but I would expect that your weight is still ok (or that you are even overweighted)

 

[decompression]

Just for info...

Weight estimation lbs (xBW) Weight Estimation kg Exposure Suit Type
Add 4lbs. Add 0.5-2kg Swimsuit or skin
About 5% About 5% 3mm one piece or shorty
About 10% About 10 %n 5mm one or two piece
About 10% + 4 to 5 lbs About 10% + 2kg 7mm two piece
About 10% + 3 to 5 lbs About 10% + 1.5 to 2 kg Shell dry suit/light undies
About 10%+ 7 to 14 lbs About 10% +3 to 6 kg Shell dry Suit with heavy
Additional 5 lbs Additional 2.2 kg Add hood/boots/gloves

2. Estimating weights differences due to changes in water salinity:
Salt water is denser than fresh water. It simply has more particles in it. When moving from fresh water to salt water, with the same equipment, we tend to float and need to add weights according to this estimation:

Body weight Weights to add (salt water)
100-125lbs/45-56kg 4lbs/2kg
126-155lbs/57-70kg 5lbs/2.3kg
156-186lbs/71-85kg 6lbs/3kg
187-217lbs/86-99kg 7lbs/3.2kg

3. Estimating weights changes due to tank/cylinder type:
We can choose to dive with tanks made of Aluminum (AL) OR Steel (ST), and in various volumes. Different tank types float differently. We want to be able to stay neutrally buoyant especially at the end of the dive, when our tanks are emptied and lighter.

Cylinder type and volume Weight change. (for Worthington steel/Luxfer aluminums)
AL80 + 3.4lbs/ 2kg
AL100 +2.1lbs/1.5kg
St HP80. -3.0lbs/1.4kg
St HP100. - 2.5lbs/1.1kg
St HP120. -2.0lbs/0.9kg

GEAR Regular set(single). Regulator set(double)
- 1 lbs - 2 lbs
Backplate SS. Backplate AL
- 6 lbs. - 2 lbs
STA. SS. STA AL.
- 2 lbs. - .5 lbs


Looks like this;
7mm wetsuit. + 25lbs
Hood/gloves/boots. + 5 lbs

BP/W. + STA(SS). - 8 lbs
Tank (1xHP 120). - 2 lbs (full - 11 lbs, change is -9lbs)
Regs. - 1 lbs

lead required ; +30 lbs minus -11 lbs = -19 lbs of lead (+9lbs air)

start of dive is; - 48 lbs (gear/lead/air)
Begin of ascent; - 42 lbs (gear/lead/air)

Positive buoyancy of gear is 30 lbs, negative buoyancy of gear is 11 lbs, lead required is 19 lbs, wing capacity for a balanced rig is 48 lbs - 30 lbs = 18(20) lbs

3mm wetsuit. +10 lbs
Tank (1xAL80). +3.4 lbs
BP/W SS +STA. - 8 lbs
Reg set. - 1 lbs

Lead required; +14 lbs minus -9 lbs = 5 lbs

Goal of a balanced rig is to use the minimum amount of negative weight and the minimum amount of lift (wing capacity) required to safely complete the dive (including all stops on ascent).

Once you’ve estimated the weights needed, its time to perform buoyancy check!

 

[Kronek]

About 10% + 3 to 5 lbs About 10% + 1.5 to 2 kg Shell dry suit/light undies
About 10%+ 7 to 14 lbs About 10% +3 to 6 kg Shell dry Suit with heavy

6mm neoprene, I would assume its the 10%+7-14?

Going through, 8lb for 250lb, ~35lb for the suit (25+10), 4lb for the tank, drops me right around where I am with weights now. Time to hit the water I guess.

 

[GrumpyOldGuy]

Time to hit the water I guess.

Keep in mind. With a wet suit you can get a good idea by simply getting in the water with a full tank and adjusting weight to float at eyeball level. Then add 4lbs for air. That 45lbs does sound high, but not unheard of for a new 250lbs diver who might be kicking a bit and/or have some air trapped someplace. My son started the same place as you (46lbs), now dives 34lbs in s/w with 7MM FJ+Jacket, he is also a 235lb XXL, the weird thing is his brother, who tops the scale at 260lbs need 30lbs in the exact same gear.

With a dry suite, it depends a lot on how much air you keep in the suite. Its pretty difficult to know this when first diving dry as your legs will me under much more pressure than you chest at the surface. You can do the same type of test, just don't be as aggressive in dropping weight when diving dry as being under weighted forces you to minimize air in the suit to the point you feel crushed.

 

[decompression]

About 10% + 3 to 5 lbs About 10% + 1.5 to 2 kg Shell dry suit/light undies
About 10%+ 7 to 14 lbs About 10% +3 to 6 kg Shell dry Suit with heavy

6mm neoprene, I would assume its the 10%+7-14?

Going through, 8lb for 250lb, ~35lb for the suit (25+10), 4lb for the tank, drops me right around where I am with weights now. Time to hit the water I guess.

10%of250=25
+7 to 14=10
+5(hood/gloves/boots)
+4(tank)
Total 44 lbs

As the suit is a 6mil suit this should be pretty close, I would consider it a bit heavy but I know the temps in Halifax can be pretty cool (30-40 deg C) so with that suit, warm undies and thick neoprene hood/gloves you should be in the ball park.

For sea water, we use scuba math for quick estimates for students (identical gear);
10% of their weight plus 10-15 lbs, depending on body type. Close enough to get them into the water for a bouyancy check.