Underwater Exploration

Jason and I met up with George Watson and his Tech 1 student (Stephen) this past weekend, with the idea to dive and talk about UTD and the classes that he is able to teach. Little did we know that George had some other plans for us. His student was solo this weekend because his team mates bailed on him at the last minute, so George wanted my buddy and I to act as his team mates so that he could practice some of the skills.

The first dive was a shakedown dive with valve drills and OOG’s. I wasn’t performing my best since I it was my first time wearing double LP72’s and I didn’t quite have the trimmed out correctly. So I was yo-yoing a bit trying to find that happy medium. After a quick debrief, George must have felt confident that we weren’t going to kill each other or him, so we did a really cool experience dive to look at some gypsum crystals growing out of a clay bank.

I must say that I’ve only dove on this site a few times, but have never really had an opportunity to explore. So this really turned out to be a real treat for me. Out of the local sites we have available, Rock Lake is truly unique. The geologic features of the spring has some similarities of some other local springs, but at the same time are dramatically different.

After a surface interval that included some land drills and George explaining how to *cough* manage some scenarios (that should have been a clue of what was to come), we were back in the water. My buddy was to blow an SMB to use as an upline, while Stephen, was to run the line south along the spring. We experienced fixable post failures, unfixable post failures, lost mask, and even an instance where we were buddy breathing because of the available working regs between us. We even experienced a couple failures that weren’t due to George, such as line entanglement and light failures. Luckily, my battery died on my primary light during deco on one of our experience dives.

On our last dive on Friday, George gave us our first dose of crack, for free of course. It was my first time to pilot an x….. I must have one… Dammit, George!

I went into the weekend expecting some simple dives and chatting up George, but what we got was completely different. It’s very cool to see how you handle failures when your head isn’t in class mode. Over all, we could have handled some things differently, but no body died and I think that’s a big plus. Two days, 11 dives, excellent weekend. I think my buddy and I will be starting our Tech 1 class with George in the early spring.

Our first dive on Saturday morning was one of the coolest dives that I’ve ever experienced. It was dark, except for our light sabers lighting up the wall. If you looked up, all you could see was a green silhouette of the surface. If you looked down, all you saw was a vast wall in front of you disappear into the abyss. And the gypsum crystals hiding in plain site stole the show for the weekend. That was a completely unexpected surprise. I loved it.

My favorite moment was when I had a left post failure, so my only breathable reg was on my primary reg, Stephen was maskless and I was guiding him up the line via touch contact, and Jason and George were having a pretty detailed underwater conversation, where George was telling Jason to go OOG and take Stephens primary regulator. Jason, being the nice guy that he is wanted to make sure that George really wanted him to do that. After a few moments, George reached down, took Stephen’s primary, and gave it to Jason. I have to admit, I was chuckling a bit by that.

I did a few dives the other weekend at Perch Lake and Blue Hole near Santa Rosa, NM. I shot some video in Perch Lake, but unfortunately the lighting conditions weren’t the greatest and none of the video really came out. It’s kind of a bummer because I was hoping to pull some still frames from the camera of an interesting rock formation in Perch Lake. It looked like a petrified barrel spounge. I’ll have to try to find it again and get some pictures of it.

The water conditions at Perch Lake were warmer than this time of the year last year. My gauge registered 51 degrees in Perch Lake, with no noticable thermalcline. Last year about this time the water temperature was around 42 degrees. So far, I’m attributing this to the mild fall that we’ve had this year. I also took some PH test strips with me to test the acidity of Blue Hole and Perch Lake. Perch Lake registered a 7.0 (Neutral) and Blue Hole tested between 6.0 – 6.5 (slightly acidic). I thought that was pretty interesting given the a lot of the people that I know complain about chapped hands, faces, and the chalky residue that is left on our gear after the dives. I always assumed that the water was alkaline. Maybe that’s changing?

I also took a some rock samples from Perch Lake and Blue Hole when I was there. I’ve been gaining some interest in geology recently, so I figured that I would take some rock samples to try to figure out the geology of the region a little better.

 First I wanted to get a generalized idea of how old the rocks are in the area. So I found a generalized Geologic Map of New Mexico and determined that most of the area dates back to the Mesozoic era, so 245 mya (million years ago). That includes the Triasic and Jurasic periods. The time period is determined by carbon dating and fossil records. I put a little red circle on the attached map, so that you could get an idea of where the region is.

The first rock sample that I took was from Perch Lake. The color of the rock is light grey with some hints of a red rust color. Perhaps rust color from an iron mineral oxidizing. It has as a fine grain and some degree of foliation. There is a slight shimmer to the rock when it’s held to the light. It’s very brittle and can be scratched by rubbing your finger against it. It does not efferves when white vinegar (dilute hydrochloric acid substitute) is applied directly on rock or when the rock is scratched.

I determined that this was a Sedimentary rock called Shale.

Perch Lake is interesting, geologically. Many of the rocks that I’ve seen along the wall of the dive seem to be very porus, much like a sponge. It’s more than likely where the water comes from, since Perch Lake doesn’t have any noticable flow like the Blue Hole does. The water temperature fluctuates with the time of the year, it forms thermalclines during the warmer months, and the water is green from algea. It’s not quite stagnate though. The barrel sponge shaped rock is very interesting though. I wonder is the rock is igneous, limestone, or some forgotten reef from a period of time when the area was covered by a shallow sea? The dive interests me more and more every time I slow down to look at the rock formations on the walls. It’s very cool and very different from the Blue Hole. I’ve only seen a single confined area in the Blue Hole that has the same sponge like rock formation.

The remaining rocks are from the Blue Hole. I’ve been trying to figure out if the Blue Hole was more of a limestone solution type cavern or a cavern formed by volcanic activity for a while. Two samples appear to be limestone, one is dolostone, and the fourth appears to be Sandstone. What else confuses me is the Blue Hole itself. The walls that form the hole are filled with cracks that run in every direction and layers. It doesn’t really bare any simularity to the holes that I’ve seen video of from places like Florida.

Here are the Limestone samples:

Sample number 3 (left hand image), initially confused me. I was starting to think that I had a metamorphic rock because it has large crystals covering about a quarter of the top of the rock. (click the image to see the crystals). I initially thought it was quartz, but soon realized that the crystals were much to soft to be quartz because I could easily scratch them with my finger nail. Once I did the ‘fizz test’ I realized that the rock was limestone.

Here is the Dolostone sample:

Here is the Sandstone:

Why do I think that the rock is sandstone? The color, hardness (stratches glass), foliation, grain size, and it doesn’t efferves with vinegar.

So, out of five rock samples, all five are sedimentary.