On any dive when you go below certain depths, the pressure increases. On the surface we are subjected to one atmosphere of pressure. At 46 feet, we are subject to 2.5 atmospheres of pressure because the water around us is way more dense than air. This means that more air can be compressed into the same volume of space. So when we breathe here, we are breathing in 2.5 the amount of air on the surface, even if it is the same volume. Make sense?
When the gases are compressed within our bodies at this depth, we are thought of as saturated, which is okay as long as we stay under pressure. However, were we to go to the surface quickly and relieve that pressure, all of those compressed gases would suddenly decompress and expand in our blood and tissues. This is known as decompression sickness, or the bends, and can cause problems ranging from disorientation, dizziness, joint pain, and ultimately death. This is why we go through the process of safe decompression. Decompression is the slow lowering of pressure, so that the gases have time to slowly expand and leave our bodies before we exit the habitat. It requires the use of a hyperbaric chamber, in which we can control the level of pressure to a fine degree of accuracy. This is where Aquarius comes in.
As part of a fun little side experiment, we put a little air into a glove at 46 feet of pressure, and placed it beside the pressure gauge. I've been taking a picture as the pressure has been dropping to see how it changes! The small amount of air placed inside the glove at 2.5 atmospheres has now blown the glove up quite a bit in the lack of pressure. We'll see what it looks like in the morning!
The pressure is still dropping in here, as we slowly ascend to surface levels. In the morning, we will be ready to repressurize the habitat so that when we open it, it will not flood with water. We will then quickly enter the water, and begin a slow ascent to the surface, just as if it were a normal dive. At that point, my journey as an aquanaut will have come to an end. As I've said before, it's a bittersweet feeling, however I am ready to feel the sun. Besides, there's still over 15 days left in the mission, and I plan to be around for as many of them as I can. Not only to continue running the experiments, but also to help the new aquanauts Liz and Grace with their work!
It was really amazing to share this experience with all of you readers, and though my words are inadequate to truly describe this journey, I'm glad you were along to read it. I plan to continue from the surface, but I will likely not be posting daily updates anymore!
For one last time from underwater on Mission 31 and the Medina Aquarius Reef Base... until tomorrow,
- Aubree Zenone, Aquanaut