Last Updated: August 9, 2023
The amount of weight you will need when scuba diving depends on many factors including your body type, your diving environment, and your diving equipment. Your body mass index and your gender can affect the amount of weight you need for diving.
Additional factors that influence how much weight you need include whether you are diving in freshwater or saltwater, how thick your diving suit is, and how much your air tank weighs. In general, your scuba weight can be calculated by dividing your body weight by ten, assuming you are diving with a 5mm suit in saltwater.
In this article, I’ll cover how your scuba weight is calculated and I’ll also go over why proper weighting in scuba diving is so important and how to conduct a weight check.
How to Calculate Scuba Weight
As a general rule, men should subtract about 6 or 7 pounds for a freshwater dive and add 6 or 7 pounds for a saltwater dive. Women should subtract 4 or 5 pounds for a freshwater dive and add 4 or 5 pounds for a saltwater dive.
Since thicker suits make you more buoyant you should also add 3 to 5 pounds if you are using a 7mm suit or 7 to 10 pounds if you are using a drysuit. For thinner suits such as 3 mm, you should divide your body weight by twenty instead of ten to find your proper dive weight. For skin diving, only use about 1 to 4 pounds of weight.
To make this easier, here’s a simple scuba weight calculator to give you an idea of aproximately how much extra weight you need.
Why is Proper Weighting When Scuba Diving Important?
There are several reasons why proper weighting is important for scuba diving. First and foremost, you won’t even be able to dive if you don’t have enough weight. If you are positively buoyant, you will not be able to get down to depth.
Even if you do fight your way down, which exerts unnecessary energy, you will probably have to deal with fighting to stay down. Floating up uncontrolled is dangerous for many reasons. If you float to the surface unintentionally due to positive buoyancy, you could risk a collision with surface traffic because you may not have time to inflate your surface marker buoy.
A more dangerous consequence of floating up is contracting decompression sickness because you will not be able to make the required safety stops to pressurize yourself gradually.
Adding too much weight can also be a problem. With more weight, you will use up your oxygen faster, and work harder to swim against tough currents. You will also be exerting more energy altogether and diving should be naturally easygoing.
Proper weighting is very important so that you can avoid the dangers of not having enough weight and the energy cost of having too much.
How to Perform a Scuba Weight Check
You will want to conduct a weight check, also known as a buoyancy check, at the surface before beginning your dive. This will help determine if you are positively, negatively, or neutrally buoyant.
Initial Weight
First, put on all of your gear including the extra weight you’ve estimated you may need based on your calculations or a scuba weight calculator you used.
Enter the Water
Enter the water in an area where it is too deep for you to stand. Put your regulator in your mouth and your mask over your eyes and nose.
Take a Breath
Take a breath and hold it. Completely deflate your BCD while you are still holding your breath and let your body hang vertically in the water. If you are neutrally buoyant, meaning you have the right amount of weight on, you will float at eye level with the surface and sink when you exhale.
So most of the time I know I am properly weighted for diving if I do this simple check.
Adjust
If you are positively buoyant, then you will be much higher than eye level without the ability to sink. In this instance, you will need to add more weight. If you are negatively buoyant, you will start sinking before you begin exhaling. This means you have too much weight and need to lighten your load.
One of the most important things to remember while conducting a weight check test is to stay as still as you can. If you tread water or kick your legs, this will force your body upwards which can falsely reveal if you are properly weighted.
It is okay to be slightly overweighted, as indicated by the sinking when you exhale, at the start of your dive because this will compensate for the shift in weight you will experience as you use air and lighten your tank during the dive.
Conclusion
Calculating the weights you need to add in order to conduct a proper dive is simple as long as you factor in all the right variables. Whether you are performing the calculations yourself or using a preconfigured scuba weight calculator, make sure you include your body mass index, gender, type of gear including suit thickness and tank material and size, and diving environment.
Ensuring the proper amount of weight to use is important not only to have a good experience diving, but also to have a safe one. Overweighting yourself can cost you time and energy during your dive, while underweighting yourself can be dangerous to your health. Perform a weight check before your dive to make sure you are neutrally buoyant so that you can have a fun, safe diving experience.
My unbounded love for the oceans and everything it has to offer motivated me to pursue my passion and become a professional scuba diving instructor.
I keep reading, exploring, and learning more about scuba diving and the underwater world all the time, so I’m excited to share my knowledge with fellow scuba enthusiasts and hopefully contribute a little to your development as a diver. I want people to fall in love with the oceans with as much passion as I have. Read more about me here.