The Cave of Wonders

You will wish you were here! Day two of the cave had a few exciting discoveries... as well as a couple of newly created set-backs. Because our sonar was out of commission the first visit, we spent all of Thursday repairing and splicing the tether that caused the problem. Today, we finally had a chance to map the cave and the wonders contained within its depths.

The newly repaired tether worked like a charm as we mapped the surface of the first pool in the cave. We also mapped varying depths at multiple locations in the cave that we hope to "paste" together. This will hopefully be enough data to completely represent the water within the pool in the cave. In addition to horizontal scans with the sonar, we ran a couple of lengths in the pool with the sonar strapped vertically to the ROV. This will provide us with two sets of dimensions to log the depth of the pool. We used this method primarily to make up for our faulty depth sensor in the ROV's control box.

After mapping the pool, I drove the ROV around to get some close up video of the sides and bottom of the pool. I found a lot of interesting things... a couple of tires and oil bins, plenty of rubble, bottles, and occasional sections of wood. One particular piece of wood had a community of water creatures... either miniature crawdads or a type of shrimp. It was pretty cool!

Unfortunately, our repaired cable suddenly failed and we lost driving ability for the robot. We switched to our other tether, but that one didn't connect sonar, so we only did visualizations from then on.

All in all, the cave was very exciting. I only wish I had my scuba gear to dive down in it!

The Cave

Today (Wednesday) we began exploring a cave at St. George's Bay in St. Julian's. It was huge! It is this large, deep pool of water contained completely in this cave. We had a bit of a trek to get to the entrance, and when we got there, we had to walk down a staircase which led to the water. We set up our equipment up near the entrance so we had some light to work in, and Andy and Brig practiced their driving skills for the first time since we've been here in Malta.

Unfortunately, like yesterday, we had a lot of technical problems with the sonar communication (a relatively new problem since Chris showed up...impeccable timing). We ended up deciding to not dedicate too much time initially to troubleshooting the problem, and get on with exploring the cave. We took a lot of video and really just wanted to get a feel for the size and environment of the cave. With 3 days to explore, we wanted the first day to be dedicated to getting a grasp on the cave as a whole.

Around lunchtime, we decided to pull the ROV out, and attempt to do some debugging on the sonar connection. We narrowed the problem down to the actual connection between the ROV and the tether, but were not able to come up with a solution on site.

Deciding to continue with just video, we put the ROV back in the water and I took control of the control box for awhile. My goal was to get as deep into the cave as possible, given the limited amount of cable we had.

After exploring for awhile, I hit a maximum depth of about 35 meters (114 feet!). I went into the cave as far as I could, and when I was pretty sure I had run out of cable, we decided to turn around. Upon trying to surface, I realized that there was a bit of a problem: I had created some significant snags in the tether while driving around. This was probably one of the worst tangles that the ROV had experienced thus far, according Chris, so as one could guess, there was a bit of stress around the cave site. Half of the team was down in the cave, waiting to wrap up the cable as it became untangled, while the other half watched the video feed and attempted to strategize a plan to untangle the ROV. Chris ran back and forth between the computer and the cave to try and quickly solve the problem so we didn't end up becoming completely stuck in this massive cave. It took quite awhile to remedy, but after some careful driving, we were free and to the surface. Getting stuck allowed us to more closely see some of the natural formations of the lower parts of the cave, which were super interesting!

With the significant technical problems of today, we have decided that it would be best to stay home and troubleshoot tomorrow instead of trying to explore the cave with non-functioning equipment. We hope that by Friday, we will be able to have the sonar connected so we can create some maps of the cave (not an easy task), and maybe even connect our second tether so we can explore even deeper!