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#50616
Diving Weight Calculator - Is it accurate?
Greg - 1/18/2013 10:10 AM
Category: Web Site Help
Replies: 47

Check out the new scuba diving weight calculator, is it pretty accurate?

http://www.divebuddy.com/calculator/weight.aspx
#6263
Eric_R - 1/18/2013 10:15 AM
I put in my values and it was telling me I needed 30 pounds of weight.LOL I use 20 pounds. So I would say NO!
#50616
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Greg - 1/18/2013 10:24 AM
From Progrower: I put in my values and it was telling me I needed 30 pounds of weight.LOL I use 20 pounds. So I would say NO!...
Look back at your log book and try a couple different variations and let me know what percent you think it’s off by. I used a few different models found online and averaged what they calculated. But if most of our results are higher, I can offset by a few pounds.
#50616
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Greg - 1/18/2013 10:33 AM
I think I’m going to split out 5mm one piece and 5mm two piece. There is a big difference between the two.
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divingbear - 1/18/2013 10:36 AM
It is a close est. every diver is a little different, I can loose 5 to 8 lbs changing diving styles in my 7 mm. But the calculator is where I weight check in at.
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WarmWaterTurner - 1/18/2013 10:55 AM
Seem a bit heavy for me as well. I used 185 pounds/3mm/al80/fresh gave me 14+/-1. I usually go about 8. Salt was a bit closer to what I actually use.
#50616
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Greg - 1/18/2013 11:00 AM
Maybe these weight calculations were designed for new divers that don’t have their breathing under control yet...and usually hold more air in their lungs than they need. I think we all can agree that when we first started diving, we used more weight than we use now. So maybe I can add a drop down to include experience level and that would offset the result a little bit.
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Scuba-Smurf - 1/18/2013 11:28 AM
Close, was 3kg’s too heavy in skin and 3mm suit which is what I wear, however it is only 1kg out from when I started so good job!
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Scubadad2 - 1/18/2013 11:43 AM
It is not always the calculator. I just got a new 8mil semi dry suit. and have had trouble just getting the buoyancy thing right. I had to use 40 lbs just to go under water for the first few dives. The calculator might be close if you are really comfortable with all the gear you use, your skills, and proficieny.
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JMorales - 1/18/2013 12:09 PM
It gave the proper weight for me. Technically I should dive at 18 lbs but since its easier to do 20 I always dive 20.
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jstatham - 1/18/2013 2:21 PM
With Drysuit no foam exposure clothing/Al80/fresh 215 lbs it put me at 31 lb. I use 20lbs
#50616
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Greg - 1/18/2013 2:25 PM
From jstatham: With Drysuit no foam exposure clothing/Al80/fresh 215 lbs it put me at 31 lb. I use 20lbs...
What is your dive experience? Novice, Proficient, Advanced, Expert.
#50616
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Greg - 1/18/2013 2:40 PM
So far it seems the ones it’s most off for are Advanced - Expert Divers.
#5771
Agojo - 1/18/2013 2:46 PM
Currently (192lbs) using 8lbs in salt water with a skin, calculator estimated 15lbs. With a 3mm/salt I use 16lbs and calculator est. 21lbs. When I started diving (first 20 dives) in fresh water with a 6.5mil 2-piece is was only 2lbs heavy. It appears to be closer for beginner/novice divers from several other scenarios I used.
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Kemperite - 1/18/2013 2:59 PM
I don’t put much faith in models or calculations for weight when diving. The calculator comes up with:

>> In Salt water, weighing 195 lbs, given the specified exposure suit and scuba tank.
>> You will need an estimated 36 lbs of weight (+/- 4 lbs).

In salt water (Florida Keys) wearing a shell dry suit and 4TH Element underwear using an AL80N tank I would generally wear 10 pounds of weight in my integrated BCD and 3.5 total pounds of weight split on my ankles. The calculator doesn’t differentiate between an AL80 and an AL80N - but that’s only a couple of pounds difference.

I’m willing to admit that I’m the exception rather than the rule. When I went through the PADI IDC/IE nobody in my class wanted to draw me for the Rescue evaulation. We did it in a freshwater lake and in a 4mm full wetsuit I would sink as soon as my BCD was removed. In a 5mm full wetsuit I can dive without weights in freshwater using an AL80N.

Many recreational BCD’s can’t offset for 35+ pounds of weight with lift capacity (many can’t even hold that much if they are weight integrated) so if I were teaching a class I’d be hesitant to put a student in the water wearing more than 24 pounds of weight unless I tried them in a pool and they simply couldn’t pass a buoyancy test with less.

Yeah Greg, I’m one of the more advanced divers you speak of...but I would proffer that many advanced divers dive with too much weight since they are not known for doing a bouyancy check once a year, let alone before each dive.
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OUBobcat - 1/18/2013 4:04 PM
Says I don’t wear enough weight. I wear 14 lbs and it says 21 lbs.
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hcdiveteambrian - 1/18/2013 4:39 PM
Right on the money! Cool Calculator Greg!
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RAWalker - 1/18/2013 10:05 PM
I actually use a LP Steel 108 in fresh water. I tried both the 100 & 120 and up to expert for both my dry suit and 3mm full it suggests far more weight than I actually use.
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RAWalker - 1/18/2013 10:12 PM
To increase the accuracy you would need more accurate tank profiles.
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divecop - 1/18/2013 11:20 PM
It had mine right on. I think maybe a height value may help. Some who is 5’7 and 190 may be different than someone 5’10 190lbs.
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RichKeller - 1/19/2013 5:20 AM
There is nothing in the calculator asking about your height. Buoyancy for a guy 6’1" at 210lbs will be different for a guy 5’8" at 210lbs.
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Greg - 1/19/2013 6:30 AM
From RichKeller: There is nothing in the calculator asking about your height. Buoyancy for a guy 6’1" at 210lbs will be different for a guy 5’8" at 210lbs....
Height shouldn’t have anything to do with it. Your body volume and density determines how buoyant you are. This could roughly equate to your body weight and muscle mass. People with more muscle than fat are less buoyant and therefore need less weight to sink.
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ScubaNut08 - 1/19/2013 9:45 AM
It was right on for me using a skin in the ocean. Will try some other situations.
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LatitudeAdjustment - 1/19/2013 10:05 AM
Heavy for me on all combos I tried but my steel tanks are 72’s, not 80’s and my 7 mil is a one peice jumpsuit which is not one of the choices. The al14 pony probably throws things off too but it’s a good starting point for people trying a new set-up.

Now where are you going to put this so visitors can find it, sticky at top of forum or new spot for utilities on the tool bar?
#50616
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Greg - 1/19/2013 12:38 PM
I’ll put a link to all calculators at the top next to local diving info. And coming soon, I’ll have a scuba quiz section :). To test how smart you all are.
#538
jshoemaker_1 - 1/19/2013 2:30 PM
Using Steel HP117’s and a 1 piece 5mm suit. I use 20 lbs. Calculator gave me a 20lbs est for 120’s. It’s within 2 lbs for me. I think widening your tank selection would be of value to many on this site.
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Scubagerl - 1/20/2013 11:03 AM
The calculator was bang on for me based on my last dive trip to the Caymans (3mm) and Red Sea (5mm).
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Green_Achers - 1/20/2013 10:47 PM
Ran my setup and it was conservatively close. I dive with 24 lbs and it estimated 27 lbs - which I could cope with.
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jimlimper - 1/22/2013 9:29 AM
I put in my info and it came up with 18lbs. I dive with 4lbs.
Body composition is really the biggest factor and most people wouldn’t know what to enter.
If you have a low % body fat, you’re going to need less weight.
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BoneCrusher - 1/23/2013 5:49 AM
Not too bad. I tried for both fresh and salt water with either a 5mm full and 3mm full as I dive both suits. For the 3mm suit it is 1 lb high in both salt and fresh water but for the 5mm full one piece it was 4lbs high in both.
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hardhat06 - 1/23/2013 8:41 AM
It came out within 2 lbs of what I use for weight.
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Nitediver - 1/23/2013 11:20 AM
Tested with both myself and my wife in both fresh and salt 3mm and 5mm. Salt is off by about 2 lbs for us both in 5mm salt but with your margin (+/- 2 lbs) that puts it in right on the money.
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caves4me - 1/24/2013 5:32 AM
The calculator put me on the heavy side for me with my recreational rig.
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MaryW - 1/24/2013 8:59 AM
mine was right on! Good job!
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NMGoose - 1/25/2013 9:35 AM
For the conditions (fresh water) I put in, the calculation was about 10 pounds heavier than what I currently dive with.
#50616
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Greg - 1/25/2013 10:23 AM
Based on the majority of your feedback, when it’s off, it’s recommends more weight than you would normally use. I guess I’d rather it recommend a little more weight than not enough. We can always add a touch of air to our BCs to compensate.
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Khou - 1/25/2013 8:00 PM
Exactly how much I use mostly of the time. However, I carry 4 extra lbs if wear BARE Hi-Loft.
#50616
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Greg - 1/29/2013 4:25 PM
I also just added an Altitude Diving Calculator if you’d like to test it out.
#50616
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Greg - 2/02/2013 7:58 AM
From LonestarDiver: It put me at 12 pounds when I dive around 5 lbs IF that much....
Did you adjust the Experience option to match your level of diving experience.
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zzzScuba - 2/24/2013 7:39 AM
Spot on.
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ShawnOlson - 3/22/2013 1:57 AM
I think its pretty close was playing back and forth with the novice to expert seem to help you fine tune it to yourself. Yeah I did use that much weight in the beginning and now I use much less weight.
Now is the algorithm readily available or willing to share cause this would be good for an app for my phone.
Or incorporated into a DiveBuddy app where we can check out the Dive Buddy website and forums and of course use the weigh calculator.
#125
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susierivers10 - 12/23/2014 10:20 AM
Closer than anything else I’ve tried out there in app land. Kudos!!!
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chrpai - 12/24/2014 9:38 AM
I think an "accurate" calculator would require me to create a profile and then enter all the gear I have. Then based on inputs from me infer back what the relative buoyancy of my various pieces of kit are and then calculate how much weight would be needed for a given selection. Make sense?
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searly28 - 10/20/2015 6:55 AM
I’m diving tomorrow in salt water. New set of steel HP100 tanks, that I’ve used in fresh and brackish (fresh/salt) water. I’ll use the calculator for an adjustment, and let you know how it turned out in a couple of days. Currently I use no weight with a skin, and the calculator says salt water will require 10lbs +or-. I think that is pretty close, as I was calculating about 8lbs minimum on my own. I cast my own weights so they are only about $1 a pound. May leave a couple of lbs on the bottom if necessary. (:
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taylorharris50 - 2/03/2016 4:31 PM
It says I should use 13 lbs with my values. I got away with 4 last week. Seems WAY off to me.