ARE YOU SCUBA DIVING WITH TOO MUCH WEIGHT?
In the six years that I’ve been a full-time dive professional, one of the most consistent issues that I’ve seen with people coming in to dive is weighting. My concern is diving with too much weight. Though it is a very widespread issue, it’s also pretty easy to fix with a good briefing and often some in-water instruction.
While I touched on the subject in my article Good Habits for New Divers, I wanted to expand on the topic and hopefully clarify why we need weights in the first place and how to know if you are diving with too much.
If you are a diver, no matter your certification level or experience, there is a good chance that you are diving with too much lead and it’s important to understand why.
Why Do We Need Weight?
Let’s back up to the beginning and discuss a bit about why we need weight in the first place. I’ll break it down the same way I do with divers on their first dive or their hundredth dive. First, we need to understand the three types of buoyancy: positive, negative and neutral.
Most humans are positively buoyant. Now, when I say positively buoyant, I mean that we float. Negative buoyancy, as you can imagine, means that something sinks. Neutral buoyancy is easiest to describe as a hovering diver. It is the act of maintaining position in the water column and neither rising nor sinking. Make sense? Tuck that away and we’ll come back to it…
Right now I want to focus on positive buoyancy. Positive buoyancy is very important on the surface; it’s what allows us to float. We can’t have too much of it on top of the water. Eventually, we need to sink to get beneath the waves.
Divers need weight if and only if they are positively buoyant with an empty BCD. I find most people to be positively buoyant on their own. This is due to body composition.
Fat is positively buoyant. Muscle is not. Therefore, a very fit and lean person who has trouble floating on their own most likely won’t need any weight at all, or maybe a touch at the end of the dive.
In the tropics, which is where I’ve based my career and where most people tend to dive, the water is normally quite warm. Many divers dive with a rash guard only, but a good percentage use a wetsuit, especially in the rainy season when the water temperature drops. Wetsuits increase the positive buoyancy of a diver, especially when it’s new. While it is true that we need to add a bit of weight, it’s usually not as much as most people think.
But back to the beginning; why do we need the weight? We need the weight to become negatively buoyant so that we can descend, and only to descend. Again, the only time we need to become negatively buoyant on a dive is to descend. Once we begin our descent, then we want to become neutrally buoyant and remain so for the remainder of the dive.
What’s The Problem With Diving Overweighted?
Crossing over from negative buoyancy to neutral buoyancy after the initial descent, we are adding air to everything. We add air to our sinus cavities, to our mask and to our lungs by continuously breathing. We are equalizing due to the constant pressure changes of the descent. The same is true with our BCD. This is difficult to do properly and efficiently if you are overweighted.
To become neutrally buoyant, we need to add air to our BCD. This air will negate the bit of weight we need to become negatively buoyant. As we descend, the bubble of air in the BCD compresses, just as the air in our sinuses, mask, etc. We need to add more air so that the air spaces remain the same size, including the air in our BCD.
The more weight we have on our body that we don’t need, the more air we need in our BCDs. This actually makes controlling buoyancy much more difficult because any depth change will drastically affect the large amount of air in the BCD.
I find the main problem is that divers get used to it. They compensate by breathing very deep and exhaling quickly throughout the dive. This will not only cause poor air consumption, but it’s also very difficult to control your position in the water column with your lungs because you are constantly in a state of negative buoyancy.
The other main way people compensate for diving in the negative state is by constantly kick themselves up to maintain position. This is dangerous for the reef, but it also causes overexertion and anxiety.
Whereas if a diver is neutrally buoyant and properly weighted throughout the dive, these issues are insubstantial.
Why Do People Dive Overweighted?
When I did my open water and advanced diving courses in Bali, I was given twelve pounds. I’m five foot eight inches or a bit over 172 centimeters. I can’t say I have much fat on me and at the time I was going to the gym about four times a week. I was pretty fit.
Needless to say, I had a very challenging time figuring out buoyancy.
It wasn’t until I became dive buddies with a vacationing instructor on a dive trip that I realized I was diving with far too much weight. He asked me “why are you diving with so much weight?” I didn’t know how to respond.
That’s what my instructor gave me and it’s what the dive guides gave me. I simply didn’t know any better. After shedding nearly all of the weight, my buoyancy was much better and I was finally able to stay behind the guide because I didn’t have to kick all the time to avoid sinking. With a shorty wetsuit, I can dive comfortably with two pounds. With twelve pounds there was a lot of air in the BCD that I didn’t need.
I find people are used to diving with too much weight mostly because they don’t understand what the purpose of weight is. This is usually due to bad instruction, and/or lazy divemastering from past guides. It turns into habitual behavior.
There have been many occasions where divers are overweighted and ask for more weight because they had buoyancy issues on a past dive. They simply had too much air in the BCD because they were struggling with being overweighted and didn’t release it properly as they ascended.
Telltale Signs You Are Diving With Too Much Lead
If you deflate your BCD and sink like a stone while breathing as deep as you please, you definitely have too much weight.
Trouble equalizing because you are descending too quickly? Drop some weight.
If you have to kick up to descend slowly, you have too much weight.
If you are actually using your BCD to compensate for the excess lead and you have loads of air in the BCD at the end of the dive, consider reducing the amount of weight you dive with.
If you can’t stop kicking, you are probably overweighted.
If you can’t get in a horizontal position, have poor air consumption and/or struggle with buoyancy, you probably have too much weight.
Adding weight is rarely the answer. Believe it or not, decreasing weight is most often the correct course of action. You don’t need to add an enormous amount of weight for a small change in wetsuit thickness in most cases (speaking of the tropics). Remember, the wetsuit will compress very quickly and cease to be so positively buoyant.
If you are breathing like a marathon runner, of course it’s going to be difficult for you to sink. If you are kicking up, it is going to be difficult to sink. Control your descent with your lungs.
The more weight you have, the bigger bubble of air you need in your BCD. The larger the bubble, the more your buoyancy will fluctuate, and you are most likely compensating in all the wrong ways.
Why waste your dive struggling? Unfortunately, there isn’t some magic formula. Take some weight off and breathe easy. If you are properly weighted and breathe like you do when you are overweighted, you will probably find yourself at the surface so be thoughtful about it. Bad habits are hard to change so start now and take it slow. Ask your guide to make sure they have a bit of extra weight. Before you know it, you’ll be diving like a pro!
Do you think you are overweighted or have any experience with overweighted divers? I’d love to hear about it! Tell me your story in the comment section below.