Its all in the trim

Perfecting Buoyancy Control

It’s not surprising that the most common injuries among divers are related to buoyancy issues—barotrauma, uncontrolled ascents, marine life injuries and more could be prevented with some practice and attention to detail.

Inefficient buoyancy control can result in descending deeper than planned, altering the intended dive profile and potentially increasing air consumption. Constant adjustments to your buoyancy control device can also affect air consumption.

The worst case scenario is an uncontrolled ascent, which places the diver at risk for a lung overexpansion injury (pulmonary barotrauma) and substantially increases the risk for an arterial gas embolism.

Ear injuries are also commonly associated with ineffective buoyancy control. During descent, if you feel uncomfortable pressure in your middle ears or sinuses, you should stop your descent, ascend until the pressure resolves, attempt to equalize and, if successful, continue to descend. If you experience a reverse block on ascent, you should descend a bit and attempt to equalize. These procedures are difficult to execute without proper buoyancy control.

Most marine life injuries result from unintentional contact between a diver and the marine life. Proper buoyancy control is essential to protect ourselves and the environment.

Ask any diver or dive professional what skill separate’s the upper and lower echelons of dive proficiency, and you’ll almost always get the same answer Buoyancy control. Divers who master buoyancy control move through the water gracefully. They seem to ascend, st6op, hover and descend at will with hardly any effort. It’s as if they think it and it happens.

By contrast those without such control constantly kick or wave to stay off the bottom. They constantly adjust their BCDs, and visibly expend effort with every depth change. They may dive safely and effectively, but not efficiently.

Few skills can do as much for you as effective buoyancy control. It’s a skill that reaches into every dive, no matter where or what you are doing. It saves you air, it saves you energy and it makes diving more enjoyable. It also helps you to avoid damage to the environment and it distinguishes you as a diver.

A lot of people dive over weighted I have seen dive centres around the world putting on a little too much weight on people just to get them down. An important rule to perfecting buoyancy is don’t wear more weight than you need. Your BCD may be able to offset a bit of excess weight, but every gram you wear that you don’t need adds to your drag and magnifies the adjustments you have to make throughout your dive.

To work out what weight, we need we need to conduct a buoyancy check or a weight check.

  • Enter the water fully equipped for a dive
  • Go to water to deep to stand up in and completely deflate your BCD (if you are diving in a drysuit ensure any automatic exhaust valve is fully open.
  • Hang vertical and motionless holding a normal breath.
  • Add/subtract weight until you float at eye level with the water while holding a normal breath.
  • When you start to exhale you should slowly start to sink.

It may take a few tries to get this exact, also be aware that at the end of the dive you will be lighter than you were when you started the dive as you use the air from your cylinder so you may want to do a weight check at the end of the dive as well. Remember your weighting will be different when diving in fresh water and salt water so you will need to conduct a weight check in both fresh and salt. You may also want to conduct a weight check when you change your dive equipment for example exposure suit, drysuit to wetsuit.

Fine tuning your buoyancy. When wearing a wetsuit or a drysuit you’ll need to adjust your buoyancy throughout your dive to account for changes firstly you’ll need to adjust as you use air from your cylinder. You will also need to adjust for lost buoyancy as you descend as pressure compresses your wetsuit or the air in your drysuit, and you will need to adjust for increased buoyancy as you ascend as your suit expands.

You can also fine tune your buoyancy with breath control using your lung volume when you inhale you tend to rise slightly, and when you exhale you tend to sink slightly. Weight distribution also plays an important factor in perfecting that buoyancy. As a rule of thumb, you want your weight forward towards your sides and stomach, which helps you maintain a neutral swimming position. Weight distribution will vary from one diver to the next it can also vary from one dive to the next.

To be able to move through the water gracefully and without effort we need to consider what we call streamlining what do I mean here, think about a car with a roof box on the top going down the motorway fully laden the car will use more fuel on its journey because the box is creating a drag as it cuts through the air which puts more effort in the car and results in more thirst for fuel. It’s the same for us in the water the less streamlined we are the more energy we will use cutting through the water. The more energy we use the more air we consume from our cylinder.

Create less drag by keeping equipment tucked in nice and tidy and easy to reach gauges easy accessible to read don’t have equipment hanging off you all over the place, when moving through the water keep as horizontal as you can and visualize how you want to be in the water this all aides to perfecting that buoyancy.

Buoyancy takes time and practise the more you get in the water and practise the more proficient you will become. The better you become with your buoyancy you will then notice differences’ in your diving you become more relaxed, this enables you to enjoy the environment around you and you can take more of it in. you will start to notice your air consumption improve as your buoyancy improves allowing us to enjoy the environment for longer.