Weight Calculator

[iguana751]

I find the PADI table to be very close to what I need in my drysuit and my wetsuit. Of course it is a rough guide because everyone's body compositon is different so no guide will be right for everyone.

 

[Drewzim]

Just completed my AOW over the weekend and noted how high PADI's weight guidelines were as noted in the peak buoyancy section. According to the guidelines in a 7 mil with hood and gloves I should be in the +/- 30# range for saltwater. With HP100's I'm down to 16#. I look back in my log to what I was wearing in my OW class and wonder how I even moved.

 

[Quero]

It's true that the PADI table is of limited use, but it's only a starting point, and each diver will vary. One thing that may be confusing is the bit about salt/fresh water change. That part is applicable to cases where the diver already knows the correct weight for one of the two. IOW, if you know you need 8 lbs for fresh, you can try adding X to move to salt, or if you already know you need 10 for salt, you can try subtracting Y for fresh.

I've picked three posts that seem to me to illustrate how the table can be misleading/misread and how to adjust your thinking to make it more helpful as a starting point.

This calculator cant be right, I wear 10lbs in a 5mil in salt water and this is saying im going to need like 23lbs. That's just dangerous.

Well, the table says a 5 mm farmer john (2-piece wetsuit), which of course puts 10mm of rubber over the core. If you were diving in a 5mm one-piece, you would start out with the calculation for a 3mm one-piece and add 2 lbs per mm of extra thickness, or 4 lbs. (Of course, this tip isn't noted in the table.) If you weigh about 170 lbs, this tip and the table will put you at a starting weight (regardless of the water) of about 12 lbs (not 23 lbs, unless you weigh 230 lbs).

I agree with East Coast...I just dove in 3mil saltwater and AL80, with a 6lb. plate and wore 2 extra lbs (total of 8 lbs). my safety stop was effortless and I really felt like I could have gone without the extra two lbs. this chart implies that I should have had 14 total lbs (8lbs on the belt, 6 in the backplate).

The weight of the backplate is supposed to be included in the total suggested in the table, not ADDED to the total. Assuming you weigh about 170 lbs (because I don't know), the table suggests you take about 8 lbs of weight total when you're using a 3mm wetsuit and carrying an aluminum 80 tank, so in addition to your 6 lb backplate, you would pick up 2 lbs to carry elsewhere. You confirm that this was the correct weight as you say your safety stop was effortless. If in fact the table is suggesting 14 lbs for you, are you saying that you weigh 280 lbs? (280 x 5% = 14)

Just completed my AOW over the weekend and noted how high PADI's weight guidelines were as noted in the peak buoyancy section. According to the guidelines in a 7 mil with hood and gloves I should be in the +/- 30# range for saltwater. With HP100's I'm down to 16#. I look back in my log to what I was wearing in my OW class and wonder how I even moved.

Here again, the the table as quoted fails to note this, but it applies only to aluminum 80 tanks. If you are diving a steel HP 100, the buoyancy characteristics of that tank are going to affect the amount of weight you need. You will always need less weight than the chart indicates when diving with a steel tank (or carrying a backplate). Fourteen pounds is a big difference, but a large chunk of that difference can be accounted for by the steel tank.

 

[WeldonDowd]

The "wing lift calculator" sticky thread at the top of the bcd forum calculates lead really well. It hit the weight requirements within a lb that the three divers I dive with regularly use for our various wetsuits and such

 

[NAM001]

I JUST weighted out my new farmer john 3 mil. i supposed it would be equivilant to a 6/3 full suit. it needs 19# for it. not counting my personal bouyancy. i would think that 30# for your example would be conservitive in that regard. my tls350 with a polortech 300 undregrment needs 38# with a 100 undergarment it needs 23# so go figure. I am 6" 250# btw. so tere is a lot of bouyant material compared to someone in the 150# weight range. So i dont see how padi can post a weight table without some sort of assumed body frame that it would apply to.

Just completed my AOW over the weekend and noted how high PADI's weight guidelines were as noted in the peak buoyancy section. According to the guidelines in a 7 mil with hood and gloves I should be in the +/- 30# range for saltwater. With HP100's I'm down to 16#. I look back in my log to what I was wearing in my OW class and wonder how I even moved.

 

[stairman]

Any chart is for ballpark weighting only. There are natural floater and sinkers. Im a floater and need a ton of weight especially in saltwater. Its a balance youll have to estimate and Id go a bit heavy so you can hold a safetystop at 20 ft with 5 - 700psi in your tank. Idealy, with a full breath holding in your lungs, you should be able to float at eye level with 700psi and sink when you exhale so you might have to wait till the first dive is over to get it dialed in properly. Make notes in your log of all equipment and amount of weight for next time too. Good luck!

 

[cwhite6]

The "wing lift calculator" sticky thread at the top of the bcd forum calculates lead really well. It hit the weight requirements within a lb that the three divers I dive with regularly use for our various wetsuits and such

Thanks!!!!

 

[Kerwin]

CochraneScuba - Basic Weighting Guidelines

I hope that helps!

Someone posted a link to an easy weight calculator to help get weight in the ballpark and I cannot find it. I also do understand you still need to do a weight test. I ask because last time I dived the DM did a proper weight check on me and I used 16# of lead in addition to my 6# SS plate. This was with a steel tank, a 7mil suit and in cold water. I will be diving next week in Destin, FL wearing a 3mil suit, an AL100 or 80 and my BP&W. I need to get close before I get on the boat as the operator I am going with gets you the weights before you get on the boat (and I have to rent them!). Anyway, any help and that link I am looking for would help a lot!

 

[fnfalman]

Figure a 3mm suit is going to require slightly less than half the weight of a 7mm suit. Figure +4lbs for AL80. Is the destination freshwater? If yes, then figure about 4lbs less weight from saltwater.

 

[Viron]

This calculator cant be right, I wear 10lbs in a 5mil in salt water and this is saying im going to need like 23lbs. That's just dangerous.

My brother that has been diving for 30 years likes to be a little heavy, especially when crawling reef or ledge in a current, but that is insane.