During your SNSI Open Water Diver course, you learned the basics about the laws that affect divers during and after a dive. A more in depth understanding of these laws of physics is necessary in order for you to better understand what happens to your body and your equipment during deep dives. Armed with this knowledge, you will be better prepared to plan and manage your deep dives.
In chapter one, we read about Archimedes Principle, how it relates to your overall buoyancy characteristics, and the variations in your buoyancy based on your depth. Pressure increases as you descend, causing air spaces to compress, including those in the dive suit, resulting in an increase in negative buoyancy. To counteract this, you must add gas to your BCD, which increases the overall volume in comparison to the water you displace.
Remember, the changes in the surrounding pressure affects air spaces, but has little to no affect on liquids or solids. Let’s take a more in-depth look at pressure.