“Trim” is one of those things that you first learn about during certification. Although on the list of priorities, it lives several rungs below running out of air and dealing with malfunctioning equipment. Trim comes with ease of buoyancy, comfort in the water, and the exactness of weight belts. Quite a bit later in my advanced training, I realized that proper weighting was, in fact, a rather controversial topic. Not only a controversial topic, but one also cloaked in conspiracy.
Adding A Few Extra Pounds
Proper trim was first brought to my attention during a dive in Jordan when a Captain strapped an extra 1.0 kg (2.2 lbs) of weight to my tank. For the duration of the dive, I was off-balance. I realized that this additional weight needed to be strapped to the dead center of my tank or I would spend my entire dive gently rotating like a rotisserie chicken.
Several months later, while prepping for two weeks of diving in Mozambique, a dive instructor asked me for my normal dive weight. I told him 6.4 kg (14.1 lbs) to which he exclaimed “WHAT!? THERE’S NO WAY!” He insisted on a controlled weight check in the pool and found my proper weight to be… 3.0 kg (6.6 lbs). “THERE’S NO WAY!” I exclaimed. “I won’t be able to sink! I’ll bob around like a cork!” So, we compromised. I would attempt to descend with 3 kg and he would dive with additional weights for me. We shook on it. And I descended.
I Had Been Carrying Too Much Weight
To my disbelief, I discovered my proper weight was 3.0 kg accounting for salt water, a 5mm wetsuit, and a negatively buoyant camera system. My neutral buoyancy was dramatically improved. I could dive and feel weightless. Moving around took less effort, fewer kicks, lower air consumption, and lengthened dive times. I no longer tipped to the right when I stopped kicking. I could cross my legs underwater and meditate at depth; rising an inch or two with each deep inhale and exhale. This was my precise proper weight, and the best part is, I now had to convince every single dive center I’ve dove with since. They fight me on it and insist on adding weight. Every time.
The Weight Conspiracy Theory
It was this same South African dive instructor who divulged his conspiracy theory to me. This was a diving industry “red pill” moment for me. Do dive shops purposely overweight their recreational divers? And why? There are two views here to which I’ve been paying very close attention.
Could it simply be that slightly overweighted divers find it easier to descend? Some recreational divers struggle with descending and slightly overweighting them assists in a smooth and immediate descent. Many recreational divers may be rusty on their specifications due to irregular dives. Time will always take its toll on memory and it’s the guide’s job to make our dives safe and enjoyable such as preventing the panic of a failed descent.
A Diabolically Clever Discovery
Now for the diabolical theory. Additional weight has a direct correlation to the amount of effort it takes to move underwater. In my experience, reducing my weight caused my air consumption to drastically improve. Strong fin kicks propelled me further and my dives took less of a physical toll because of my newfound neutral weightlessness. In doing so, my dives lasted considerably longer. Might this be to the detriment of the dive centers? Are they overweighting their recreational divers in order to increase overall air consumption and shorten dives? Shorter, faster dives could benefit dive centers in a number of ways. Less time in the water could mean decreased liability, potentially more dives in a given day, less gas needed for the boats, and cost savings on hourly paid employees.
The Bottom Line
Finding your precise trim management takes time. It can fluctuate because of water salinity, the thickness of your wetsuit, how much your camera and lights weigh, perhaps even what you had for breakfast. But do take the time to determine how much weight you should carry on your belt or BC –– and your diving will be better for it.
About The Author
Carly Anderson is an underwater photographer, scuba diver, adventurer, writer, and world traveler from Albuquerque, New Mexico, who is obsessed with adding new destinations to her worldwide bucket list. Follow her at @globalcolorpop on Instagram.