Me demonstrating perfect buoyancy and trim at the James Bond Wrecks

Once you have mastered the basic skills that allow you to dive all divers should then become experts in buoyancy control. I work hard with my students to ensure that they can move seamlessly from swimming to hovering. Not all of them are experts by the time I am finished with them but they are better than the average diver that I see at the local dive shops, and they know that they have the skills to improve.

No one really taught me buoyancy skills. Or perhaps I don’t really remember being taught them when I first learnt to dive; my Open Water and Advanced courses are a blur to me. However, I do remember seeing a some divers, probably back in 2012, that had perfect buoyancy and trim and I said to myself, “I want to look like that.” Since then I have strived to improve my buoyancy skills.

In 2013 I did a lot of speciality diving (this was back near the time when I started this blog). I had just come back from a weeks diving in Marsa Alam, where I had encountered a fantastic diver who had the perfect aforementioned buoyancy and trim. This reminded me of my quest to become better at it. So I signed up for a Peak Performance Buoyancy course in the hope that it would help improve my skills. The course was useful but I wasn’t taught everything that I have learned since, or it wasn’t exactly explained to me. During my speciality diving holiday I decided to do a PADI Tec Sidemount course and this opened my eyes to the need for having good buoyancy skills, as the video of me using a DSMB showed that I needed a lot of work.

What is the difference between buoyancy and trim?

The difference between them is really simple. Buoyancy is your ability to hover in the water, position is irrelevant. So if you can hover vertically then you can hover. Ideally you should be able to hover into any position. Therefore, trim is about how horizontal you are.  If you look at my picture above you will see that I am perfectly horizontal in the water.

Overweighting

Most divers dive overweighted. This normally stems from their first training dives. They think it is better to be overweighted so that they sink. The logic behind this makes some sense however it is flawed. If you are underweighted you won’t descend so you can’t make the dive, but if you are overweighted you can descend and you can counter the weight by adding air to your BCD. An extra 1lb of lead can mean up to an extra litre of air in the BCD, meaning greater air consumption. This isn’t what you should do. You should be weighted correctly. Being overweighted also means that your trim might be off meaning that you have to continually adjust the air in your BCD to avoid rapid ascents and descents.

To be weighted correctly you should perform two weight checks on your dive. Most instructors/dive leaders advocate the first weight check only, they might not even consider the second weight check. The first weight check is done by holding a normal breath at the surface you should float at eye-level with a completely empty BCD. When you exhale you descend. All divers usually perform this weight check. The second weight check is done at the end of the dive and should be performed at the safety stop. Ideally you should be able to hover comfortably at the safety stop with no air in your BCD. So at the safety stop, make sure your BCD is completely empty. If you find that you have a lot of air in your BCD you might be over weighted. Remove some of the weight for your next dive and perform both weight checks on your next dive. Keep doing this until you find a correct balance. You should regularly assess your weight needs, especially if you change any equipment.

I have since worked on my buoyancy and trim skills. I work on them on every dive. I know I am good at it as I have seen video evidence and I am regularly complimented and asked about my skills. However,  I am not complacent, I practice and practice and practice.

Breath Control

A little underdeveloped skill is breath control. It might be that it hasn’t been pointed out to the diver or it might be that it hasn’t bee practised correctly. In my opinion once you have adjusted your BCD for the depth you are at you should try to limit any further adjustments as this wastes your air. Some things to think about

1. If you start to ascend, the first thing you should do is exhale quickly to reduce the upwards buoyancy. If this fails, remove small amounts of air from your BCD
2. Similarly, if you are descending, inhale and see if that stops you. If it doesn’t add a small amount of air to the BCD.

Trim

Get horizontal. Being horizontal means that when you fin you will move horizontally. If you are overweighted or underweighted then you will probably have a diagonal position in the water. So when you fin you will either propel yourself up or down through the water. This will affect the air in the BCD meaning you will either have to add or remove some from your BCD, not an ideal situation as you waste air. If you require a lot of weight to dive then you might need to distribute it to other places than your waist. Some BCDs have trim weight pockets built in or you can buy pockets to attach to the camband that allow you to have more weight further up your body, helping you to remove the diagonal position.

Exercises

Here are some simple exercises that you can practice on every dive.

The weight pick-up exercise is a great way to work on your breath control. Take a 2-4lbs weight and have it on the bottom. Adjust your BCD for neutral buoyancy. When you go to pick up the weight, inhale. You should still be able to maintain your hover. When you put the weight down, exhale. Practice this skill as it will help develop breath control.

Another great skill is working with a spool, this really promotes your hovering and trim skills. Find an instructor who is willing to show you how to use a spool properly as it will sky-rocket your skills.

Hover on the safety stop, as long as conditions allow. Too many divers hold on to the descent line causing a huge crowding. The descent line can move up and down which can cause you to rise up too quickly and increase your chances of DCI.  I can’t stand being part of THAT crowd so I keep my distance and hover between 5-6m using breath control to keep me there. If there is a small current, I face into it looking at the descent line otherwise you could easily be blown away and have a horrible swim back to the boat.

Take the Peak Performance Buoyancy course or something similar. It won’t make you an expert overnight but it will help you improve and buoyancy and trim should be practised on every dive you will soon become good at it. Being able to hover is a very important skill. Too many people neglect these skills and as such cause damage to the reefs, or destroy visibility. You don’t want to be that guy who ruins it for everyone else.