04 Jan Proper Weighting Procedure for Divers
We get asked about weighting needs quite a bit in many forums, and I wanted to share with you all how you can figure out this basic task and make it accurate for you specifically. This is applicable across all exposure suits and for recreational and technical diving.
The problem is....Using an online calculator, or guessing based on someone else is poor practice and not accurate. It will most likely cause your weighting to be way off.
— SO LETS BEGIN —It doesn’t matter what someone else needs to get down as each person is different. Putting your gear on and jumping in to determine what makes you neutral is incorrect. The weight of your gear doesn’t change. The only thing that changes is the weight of the gas in your cylinder choice.
How are you weighting yourself? Did you put all your gear on then jump in pool? Did you grab weights pool side and were only in your exposure protection? Did someone guess based on your weight, or a divemaster tell you what you need?
How did you verify you were correctly weighted? Did you dump remaining air from Buoyancy Compensator Device (BCD) at end of dive? Sunk to bottom and figured it was “good enough?”
- With no exposure protection, jump in the water. With half lung volume, you should be floating at EYEBROW level. Then, exhale everything and you should sink. If you don’t, grab 2 pounds and do it again. This determines YOUR NATURAL NEUTRAL buoyancy aka the STARTING POINT.
- Now, put on your exposure protection and do this again. Also, when you jump in, open your neck seal and flood inside of your wetsuit. Keep weights poolside to increase by 1 pound each time. This will allow you to find your PROPER amount of weight to make you, in your exposure protection (REGARDLESS OF THE MM SIZE) to be NEUTRAL.
- What is NEUTRALLY BUOYANT and BALANCED? When you are at 10-15 feet, with ZERO AIR in your BCD, and you can go up or down by breathe control alone. Your tank should be between 800-1000PSI when testing. If you get to 15 ft, deflate your BCD, and sink, you are too heavy.
- NOW, let’s look at your gear….what are you diving with? If you are using an AL80 or a Steel LP85, there is only a 1.5lb difference in them….your First stage will make up for that difference as it is solid brass/metal. If you are diving with a steel HP100, you can remove 2-3 pounds from your weight setup (swing in buoyancy compared to AL80/LP85). Both Aluminum 80 and Low-Pressure 85 cylinders are positive at end of dive.
So how does this play together? YOU TAKE THE POSITIVE FORCE of you in your wetsuit compared to the NEGATIVE BALLAST of your gear (do NOT include tank unless steel HP100 (-3): 6lb backplate, negative fins (typically are around -1lb each in water), Primary Lights, Single Tank Adapter (-1.5), etc etc….
IF the NEGATIVE WEIGHT of GEAR equals the amount of LEAD you needed in pool to be NEUTRAL, then you have a balanced setup. If you have more POSITIVE force, then you need to add weight (-3 with HP100, weight belt, etc) to balance it out.
Please post any questions below. Cheers!