In The Navy (Sub School), Part 6

The Dive Tank stands about 5 stories tall, maybe a bit more.

http://www.geocities.com/Pentagon/6262/divetowr.jpg (yeah, a really old picture, but the tower is still there)

The photo below is older, before they enclosed the walkways to the Elevator. I pity the poor bastards that had to walk that plank in the winter, soaking wet.

http://www.csp.navy.mil/images/dt9.jpg

It’s a cylinder around 25 feet across, except at the top, with a stairwell winding up the outside and an elevator to come down on. At the top is a platform that rings the cylinder, which is filled with water. There are two pressure equalization tanks/entrances to the cylinder at about 20 and 50 feet from the top. The class was broken up into small groups and each marched up to the 50 foot depth tank entrance. We all had our Stanky Hoods (I didn’t make up the name) which is a plastic hood that you strap on when you get into the tank.

I think the hoods got the name because they were reused over and over in the trainer and got a bit smelly. They start equalizing the pressure in the tank with the water inside the cylinder. The tank also started to fill up with water. A last check was made of each of our getups by the instructor who was also turning valves to adjust the pressure and flood the tank. It’s so cramped and dark that anyone, I repeat anyone, who has an ounce of claustrophobia would crap his pants. Thus, the value of Sub School is realized.

We were taught in class what to do once they open the door and we swim into the cylindrical main tank. We were to not speed swim to the surface, but rather float up. The whole way up we had to repeat “Ho Ho Ho” over and over. If you failed to do so, the air in your lungs would expand and you would probably wind up in the Hospital. The depth was not great, but it was enough to significantly compress your last breath of air quite a bit, compared to the air at the surface. The hood provided an air bubble for you to keep your head in, I think to just help prevent panic.

https://www.npdc.navy.mil/slc/nss/etf041901.htm

So we were all set, and lastly told, once you get to the surface, give a thumbs up so they know you are ok. The door swung open and the first guy stepped out, you had to duck your head under the water to get through the smaller hatch. Once he stepped out onto the even darker main cylinder tank, he pushed off the edge and floated up. I may have been the second, I was certainly at the front of our group. It was pretty scary and I was consciously trying to keep calm and breathe normally.

I stepped into the void and pushed away from the edge toward the center of the tank. I had to fight the urge to kick my legs and arms to swim up. I started the Ho Ho Ho and looked up. I seemed very deep in the water, certainly a personal record. The upper front of the hood was clear and I saw several divers at various depths that were monitoring us on the way up. That was actually pretty soothing and I even smiled. Later I imagined why these guys were needed. Someone must have panicked in the past and gotten hurt, freaked out and maybe drowned.

I performed well and once I broke the surface, I gave the thumbs up and lugged myself to the edge of the pool. It was a little hard to swim in the getup. I was given a pat on the back and moved to a side wall out of the way, while everyone else came up. We had no incidents and on the way down in the elevator, we all smiled at each other and had a few high 5s in celebration. Everyone was glad to have that over.

Two of three contests done, and passed!