Once you achieve buoyancy control as a diver, you'll have a lot more freedom beneath the waves to enjoy your dive to the fullest.
It'll allow you to take gorgeous underwater photos and videos while moving efficiently through the water without touching any of the delicate marine life you're observing.
And you'll reduce your consumption of much-needed air and dramatically reduce the risks of accidents, injuries, and emergencies under water.
If you need help achieving proper buoyancy, continue reading to learn more.
Factors That Affect Buoyancy Control
The following six factors will have an effect on your buoyancy:
- How much your BCD is inflated
- How much lead you're wearing
- Your exposure suit
- Your breath control
- Your depth
- Your trim
Always Weight Yourself Appropriately
The most common cause of having difficulty with buoyancy, especially for new divers, is the inability to properly weight oneself. Many dive instructors will over-weight new divers in an effort to prevent accidents and give divers the ability to stay underwater and ascend, when ready, with more control.
And these same divers are then reluctant to change the way they weigh themselves for fear of their safety. To compensate, they'll add air to the BCD, but this results in increased drag. As you move further down into the water, the varying depths cause the air within the BCD to contract and expand, and this requires constant readjustment on the part of the diver.
To achieve the lowest possible amount of BCD inflation, head beneath the waves with the least amount of necessary weight. Find that minimum, and you'll be able to achieve buoyancy control more effectively.
Boyle's Law is one of the laws of physics that applies to diving. This law states that the number will be the same when you multiply the volume of gas by the pressure that surrounds the gas.
In other words, when the surrounding pressure goes up, the gas volume goes down, and vice versa. So this means the volume of air in your exposure suit, BCD, lungs, or cylinder will drop as you descend and as the water pressure rises.
On the other hand, it'll go up as you ascend and as the water pressure goes down. As a result, your breath control and equipment will directly affect your buoyancy. The only problem is that this law applies when the temperature is constant. If the temperature of a gas were to go up or down, Boyle's Law can't be applied.
Perfect the Way You Position Your Body
Your body position, which is known as your trim, also affects your buoyancy control. For example, if you're unable to align your fins horizontally with the rest of your body, your kicks will move you down or up instead of forward. You'll end up compensating by dumping or adding air from the BCD. This, in turn, will ruin the balance required when it comes to achieving neutral buoyancy.
First, get neutral buoyancy. Then move your body horizontally, stretching your legs back. Make sure your legs don't float or sink by correcting the positioning of the weights.
As excessive weight set around the waist will only serve to drag the hips further down, and weights that aren't spaced evenly will also pull you towards one side. Both of these situations will prevent you from streamlining yourself and moving efficiently and effortlessly through the water.
Women may even choose to use ankle weights to keep their legs from being too buoyant. And to give your BCD the chance to empty completely of air, descend with your feet first.
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Adjust Your Weights Depending on Conditions and Equipment
Weighting will change depending upon the style and thickness of your exposure suit and also the type of cylinder you're using. For example, aluminum cylinders are more buoyant when compared to those made of steel.
All cylinders are more buoyant when they're empty, it's best to don an extra 5lbs of weight before heading into the water, as this will counter 5lbs of air that's utilized when your once-full tank is at 500 psi.
Every exposure suit will be buoyant as a result of the air that's trapped within neoprene. But when you dive into deeper depths, the air in your suit will compress, and you'll lose this buoyancy. For this reason, you'll be required to add more air to the BCD to compensate.
Other reasons, why you may need to alter your normal weighting, would include deep dives, dives that take place in harsh currents and changing from fresh water to salt water or the other way around. Always remember that if you're neutrally buoyant while in salt water, you'll automatically be negatively buoyant upon entering fresh water, so you'll need to adjust the weight appropriately.
Control Your Breath
You shouldn't ever use the inflate button when ascending. Rather, use your lungs properly. Breathe out to descend and breathe in to ascend. To prevent changes to your buoyancy, you also want to be certain you're breathing consistently and evenly throughout the dive.
New divers may choose to over-weight themselves to counteract their deep or erratic breaths from anxiety at a new dive site. Learning the proper breathing techniques will prevent you from having to rely upon alterations to your BCD during a dive.
Never Forget a Buoyancy Check
The amount of weight you'll need will vary depending upon the dive site and its conditions, but you should always perform a standard and really easy buoyancy check.
Always test your buoyancy towards the completion of the first dive of the day. Once your tank is almost empty, empty the BCD completely while you're at the surface. Hold one breath so that you float at the surface around eye level.
Change the weight as necessary for the rest of the dives you'll enjoy that day. Once you find the correct weight, you'll be just a bit negatively buoyant when you reach the 3-minute safety stop, so use this opportunity to check again. A dive buddy can assist you in removing or adding weights until you find the perfect configuration.
Check out PADI's Peak Performance Buoyancy course or the Perfect Buoyancy course offered by SSI. You'll be able to learn buoyancy strategies from an instructor in a controlled environment.
You'll practice streamlining your body, making exact adjustments to trim and weight, configuring equipment, and even some relaxation techniques. You'll focus only on how to correct and perfect your buoyancy.
Avoid Using Your Hands
It's inefficient to try to use your hands to affect your buoyancy. You'll be wasting air and energy by trying to reposition your body and move underwater using your arms and hands, as most of the power that you have comes from your legs. Instead, learn to control buoyancy using your BCD, your lungs, and your fins.
Keep a Dive Log
If you log all your dives, including how much weight you used, as well as details about your wetsuit and the conditions of the dive, you can find a pattern to help you weight yourself just right next time.
Know Your BCD Very Well
You should get to know how to use your BCD very well before going on any dive. After all, it's the most vital piece of equipment you'll use to achieve proper buoyancy.
Accidents can and do occur when divers don't know how to use a BCD correctly.
Note where the dump valves are and know how they operate and make sure it fits you perfectly. If your BCD is too large or too little, you'll find it much harder to get proper buoyancy.
Also, a BCD should never restrict your body or pinch it during a dive. And avoid solely relying upon your inflator hose when it comes to releasing air from your BCD, even though this is what you were probably taught in your entry-level courses. If you're in a position where your head is down, this is an inefficient method that should be avoided.
With these tips in mind, you can rest assured that every dive will be as enjoyable as possible and that you'll have to put in less effort to achieve buoyancy control.
How did you Improve Your Buoyancy Control? Let us know in the comments below
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Article written by Rutger Thole who is an avid scuba diver and loves to travel, dive and write about scuba diving. Based in Amsterdam he runs bookyourdive.com and at least twice a year he plans a dive trip of the beaten track.