Powder in SaltLake

We really lucked out this year- doing the annual Rougetide snowboarding trip to Salt lake City this year. We decided to hit Solitude- and were greeted with snow all day! It was the best conditions I have skied! More pics and updates to come!

Dry SCUBA diving

It's a riddle. I'm going diving- but not getting wet. I'll be putting an entry into my dive log, but won't be near the ocean?

I'm participating in a DAN and US Navy-sponsored study called 'Flying after Diving' held at the Center for Hyperbaric Medicine. This research is important to me because I was in the Navy once-upon-a-time. These days, having to wait 24 hours before flying really cramps your vacation schedule.

The particular study was an aggressive one. We did a 60' dive for 2 hours- that's a decompression dive, so we 'came up' to 10' for 26 minutes for decompression. We then had a 3-hour surface interval, followed by a 4-hour flight.

The dive itself is pretty sketchy- I don't like being out of control. You're in the chamber- just hanging out- and air starts rushing in. You're having to equalize- and pretty often. I think I was doing it too often because only every-other pre-squeeze resulted in my ears clearing. The part I didn't like was that you don't have control of your descent- it is a controlled rate. When I'm diving, if I have problems equalizing, I'll just stay at that depth for a second or go up a little bit. This ride is straight down- though they told us to let them know if we can't equalize for some reason. The absolute weirdest thing was speaking- it was like we were on helium (Donald Duck voices)- but we were just breathing air. I was embarrassed to speak because the deeper your voice, the greater the effect. It was just because of the higher density of air. They told of experiments to 2000+ feet where divers couldn't understand each other from this effect. They actually had to use headsets to lower the frequency to communicate.

Once at depth, the lights went out and we watched a movie. Pretty cool- they hang a sheet on the far end of the chamber, and use a little projector through one of the portholes. The movie was 'The Big Blue'. It's French. Here's an excellent summary. It was actually not the best movie to see while testing for decompression sickness.

Anyway, we ate lunch during the surface interval (and used the head, sheesh!) walked around and such- and then back to sealab.

This was the 'dangerous' part of the experiment. They test shorter and shorter intervals at sea level before you fly. 12 participants had already done this dive without DCS. We nine were part of a study group to help finalize this test as 'passed'- the next test will be with a two-hour interval.

During the 4-hour flight, every 30 minutes during the flight they would use a doppler system to test for bubbles passing through your pulmonary artery into your heart. Since there's less pressure at 8000 feet, a gas (Nitrogen) will come out of solution faster. Nitrogen in your tissues first starts showing up in your blood as the blood circulates around the tissues. In the case of flying, the lower pressure might cause it to come out of solution in the form of bubbles instead of a controlled off-gassing. The painful part is when it shows up in your joints (hence, the bends). About 1.5 hours into the flight, I started having bubbles observed- as did pretty much everyone else. They use a fancy stethoscope (doppler ultrasound) which transmits a fixed frequency and listens for the return. Bubbles make a swishing sound a trained technician can detect. They rate the bubbles from 0-4 with 0 being nothing observed and 4 being the sound of bubbles is louder than the sound of the heart valves themselves. Doing some amount of physical activity forces bubbles out of your muscles and joints and into the bloodstream. We would flex each arm and leg, rotating the joints, while the technician listened. If bubbles were found, we then had a second test where a doctor used an ultrasound to examine the chambers of the heart. That was very interesting- watching your own heart. What they look for in that test is to make sure that no bubbles are seen in the left-chamber of the heart. The right chamber is what pumps the blood to the lungs where they do an excellent job of filtering the nitrogen. If any make it back into the left chamber- DANGER- that means bubbles are headed to the brain. For some reason, every time I flexed my left leg, I'd get bubbles of grade '3' every time, all the way to the end of the flight. I had to even get tested post-flight to make sure the bubbles subsided. I was back to zero on all the tests 10 minutes after the flight- but it was a real eye (ear?) opener to see the real effects of a gas coming out of solution. But, I- and everyone else- passed- because we didn't get DCS.

I got some good data for myself. Exertion really does make the bubbles form. There would be no bubbles at rest, but I would almost spike when I flexed my muscles. Take it easy on your surface interval and after your dive. Once bubbles form, they slow the off-gassing because the nitrogen clusters around the bubbles, rather than desaturate. I also learned that older (I was by far the oldest diver- bunch of college kids were the rest) male divers are more prone to bubble formation (but not necessarily DCS). And, it is known that fat absorbs much more nitrogen than lean body tissue- I'm happy that at 17%, I was less fatty than several of the 20-year-my-junior college kids. Probably the biggest risk factor is a condition (read the DCS link) where your heart has a hole between the chambers (left over from the fetus). Most of those that have had DCS had this condition. I'm pretty sure that my effervescence, but negative on the right-side-heart shows that I'm safe as far as that.

For me, it is going to make me a tad more careful about planning my trips (no fricking way will my 'passing' a 3-hour interval before flying make me try it).

There are a bunch of other studies coming up with that I might try as well- I really pumped the doctors and staff for information and got some good info. For example- the doctor kind of discounted the 'hydration' thing as a huge factor in DCS- compared to time and depth. On the other hand, if you are damn cold before you start a dive (everyone is cold at the end of a dive), you're much less likely to absorb nitrogen into your tissues during the dive.

Really cool bunch of guys to go 'diving' with- you get a little pocket change, you help the science of the sport you love, and you get to sit around, eat food and watch movies and BS with a bunch of divers- without getting wet.