posted on April 19, 2001 10:40:42 PM
Yesterday I went with a group from my scuba school to the Hyperbaric Chamber on Catalina Island. We went into the chamber (in two groups) and were "taken down" to 170 feet. I have never gone deeper than 100 feet since I started scuba, and I wanted to do this in order to experience nitrogen narcosis & see how it would affect me. It was a very interesting experience! For any interested, I have cut and pasted the writeup for my dive log (it's a bit *long*, I warn you ).
Catalina Hyperbaric Chamber Dive, Wednesday, April 18
We started out at 7:15 am this morning--but our start was delayed by engine trouble, so it was 7:45 before we really got under way. There was a lot of og & the water was as smooth as glass. At one point there was a hug pod of dolphins escorting the boat & many riding our bow. Arrived at Catalina at about 9:45 am.
The hyperbaric chamber looks like a huge iron lung and they are busy spiffing it up for Chamber Day next month, so were seeing it in its grey-primer glory before the final new coat of blue paint. It will hold 8 people at a time, so our group split into two. I was part of the second group to go into the chamber. The first group had to restart when one of its members couldn't clear his ears, so they "brought him back up" and let him out of the chamber before taking the first group back down. It was interesting to note that while they were increasing the pressure in the chamber, the pipes on the outside that the air was going through became very cold, throwing off a lot of whisps of cloud-like air. And when you touch the pipes, you immediately feel the heat being leeched away from you--feels a bit like it is being sucked out of you. We could watch the first group through a series of port holes along the side of the chamber.
When it was my group's turn, we took off our shoes as instructed before heading into the chamber. Most of us were in shorts & t-shirts, but I also took in some sweats, which turned out to be a good thing. The inside of the chamber is divided into two sections--a smaller airlock part, and the large rear section wear people are actually treated. One wall of the chamber has bunks while the other has built in seats. There are several lights along the ceiling & a ceiling mounting video camera which all are encased in a special glass & which maintain the outside air pressure regardless of what the interior of the chamber is at. A bucket of water was provided for those of us who brought in our dive computers (the water was to prevent any danger from sparks). A mallet hung on the wall is intended to be used to signal the outside in case the radio breaks down. Several oxygen masks of a type similar to those of fighter pilots (and, I was told, made by the same manufacturer) hang from the ceiling. For long stays there is even an invalid toilet chair in the airchamber section.
We started "down," all of us continually clearing our ears and, as requested, displaying the "OK" signal. Immediately, the chamber began to grow warm. And it was *loud*. The more they increased the pressure, the louder it got. As we went "deeper" our voices began to change in the same way they do when you inhale helium. All of us began to sound like Alvin & the Chipmunks. Two blown-up balloons we'd taken in with us began to shrink. It got hotter & hotter until the thermometer display inside the chamber maxed out at 120 degrees! We had been scheduled to be taken down to 165 feet, but ended up at 170 feet. I noticed a tingling around my facial area and a feeling of dizziness. There was one of those toddler shape puzzles in the chamber, the kind in the form of a box with different shapes cut out of its sides & pieces that are supposed to be put through the appropriate hole. We were *supposed* to each have a go at it, but for some reason my attention just zeroed in on it and it seemed the most important thing to FINISH that puzzle! I was aware of the others around me, but only the puzzle seemed important at the time. When I put the last one in (there were 10-15 shapes), I discovered the tender who was in the chamber with us by my shoulder, timing me. It had taken me a bit over two minutes to complete what is normally a very simple task.
We stayed at 170 feet for about 4 1/2 minutes, then began our ascent. We'd been told not to cross our legs or arms & to try to have them as straight as possible to prevent bubbles building up more than necessary. It began to get cold immediately & I scrambled into my sweats. I was the only one to take some in & I was glad for them. The temperature dropped to about 40 degrees. Dense fog formed in the chamber & it was difficult to see each other. We stopped at 30 feet for 8-10 minutes & the fog cleared, but when we ascended again to 20 feet, the fog came back a bit but nowhere near as much as it had been. We stayed at 20 feet for 11 minutes before ascending to our final stop at 10 feet. At this point we all put on our air masks and breathed pure oxygen. Like those of fighter pilots, these masks have a four-point strap system so that they are "hands-free". In the past, we were told, people who held their masks on, often developed bubble problems in the arm that was bent to hold it. This way we could keep out arms straight. When the time was up we ascended the rest of the way and, when the pressure had equalized, exited through the airlock.
I went on this chamber dive because I wanted to know what it feels like to be really narced, and to see how I would cope with it. Other than the dizziness and tingling, I didn't feel any physical symptoms, but the *mental* symptoms were interesting. I doubt I will ever go this deep in "real life" however--I have been down to 100 feet a few times times & found that there just isn't as much to see at those depths. For myself, I would rather stay in the 35-80 foot range & not only get to see much more wildlife, but also get to stay down for longer periods. But this was an interesting experience that I wouldn't have missed for the world.
posted on April 20, 2001 04:33:08 AM
The heat up and cool down are a natural result of compressing gas and then releasing it. If they wanted to spend the money they could run the compression through a heat exchanger like a turbo charged car often does to chill it and have some electric heaters for the decompression cycle.
Does anyone have a chamber like this for testing different gas mixes?
posted on April 20, 2001 05:59:06 AM
Wow what an exciting couple of days you have had, Congratulations on you magnificent feat.
I have to admit that there is no way known to man or woman that I would ever even consider going diving, I am just not that brave or adventurous. It would freak me out to have to go under water that deep. I think I was a witch in a previous life and they drowned me for my sins. LOL It could account for my fear of deep water.
I am so happy for you, and you really do inspire me to do something exciting with my life, just so long as I don't have to go under water to do it. LOL
posted on April 20, 2001 06:21:54 AM
Sounds like a really cool adventure for you Bunnicula! I like to hear about people learning and doing "new and challanging" things.
I love watching film of underwater scenes, but could never myself cope with going under. I even have a tough time watching movies like The Abyss because I feel like I can't breath. I tend to be a little claustraphobic.
).
