Tonight we spent 3 hours practicing our scuba buoyancy at ScubaCenter in Egan by navigating a series of underwater diamonds about 1.3 meters square. The diamonds were positioned at different depths and were numbered so that there was a specific sequence you needed to navigate.
The objective was to navigate the entire course in full scuba gear without making any contact with the diamonds. To active this objective you need to first determine the amount of “ballast” weight you need to carry to have near neutral buoyancy. Second, you need to beware of the effect of your breathing on your buoyancy, you become more buoyant as you inhale air from your scuba tank and less buoyant as you exhale. Breathing is one of the keys to fine tuning so that you are neutrally buoyant at the right depth as you pass through each diamond.
Finally as you use the air in your tank this increases you buoyancy as well. A full tank has about 2 lbs of negative buoyancy but a used tank will add about 2 lbs positive buoyancy. As time passed and air was consumed this shift of potentially 4 lbs in buoyancy became very noticeable and the course became more difficult and required more concentration.
It was an excellent learning experience and one that I have never mastered previously, I am not sure I have even mastered it now but I do have much more of a feeling of how to control my buoyancy and how to determine the correct amount of ballast weight. This will be very helpful as we move forward and everyone is now much more comfortable and confident with doing a cenotes dive.