Project Day 11: 9 March 2011
Today is our last day of diving for the project. The plan was to try to do two coordinated rebreather/Pisces V dives. The first would be the final return to CJ's "Pulse-Chase" experiment site (see Day 1), to collect the coral samples and the temperature data loggers. The second was planned for a deep ledge that Terry Kerby and Brian Popp had found during the first leg of the cruise. CJ Bradley and Ross Langston were going to do the first dive, and Dave Pence and I were going to do the second. The interesting part of the plan was that, after the first dive, we would recover the marker bouy and pass it back to the KoK. The sub would then return to the surface and the crew of the KoK would place the marker bouy back on the front of the submersible, which would descend back down to the ledge.
Unfortunately, Mother Nature has a way of foiling the best-laid plans. When Pisces V submersible pilot Max Cremer got to CJ's study site, he found that the current was extremely strong. We decided that it would be too difficult for the divers to try to descend onto the site with such a strong current, so we decided to wait for an hour or so to see if the current would subside. The sub went off to do some planned fish surveys while the rebreather divers waited in the dive boat. Thankfully, the weather was beautiful and the sea very calm, so it was a pleasant wait. Finally we got the report that the current had slacked off considerably, so we were able to make the dive. Unfortunately, we decided there wasn't enough time to complete both dives today, so we focused entirely on recovering CJ's samples. The dive team consisted of CJ, Ross, and myself. Ross would swim directly to the maker buoy anchor and send it to the surface; CJ would descend directly to the Pisces V to begin collecting her samples, and I would hover above and take videos. The dive plan went off perfectly, except for one thing: One of the two sets of coral samples she had set up was gone. The experiment included two sets of corals -- one tagged while exposed to sunlight, and one tagged while under a blackened dome, simulating night. Throughout the project, when we've returned to the site, both sets were there. However today, at the end of the project, only the day set was there. The entire night set had simply disappeared. Given the strength of the morning current, we believe the missing sample was simply carried away with the current. We did'nt have much time to look around for it, so CJ got the "day" samples and the temperature loggers, and we finished the dive.
Overall, we are very pleased with how this operation went. We had expected more complications in trying to coordinate the submersible and rebreather diver operations, but once we worked out a few kinks in the communication protocol early on, the rest of the dives went off very well. We don't know if or when we'll ever have a chance to try this again, but if we do, we're confident it can be done safely and effectively. We'll spend tomorrow packing up all our gear, and then we head home on Friday. Mission Accomplished!
Click this link for the day's Video Highlights. Video by R.L. Pyle
| Images: | Click on the small images below to see the the full-size image file. |
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CJ Bradley descends towards the Pisces V submersible, to collect the coral samples from her "pulse-chase" experiment. Photo: R.L. Pyle. |
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CJ Bradley collects the corals from her experiment, as the Pisces V looks on. Photo: R.L. Pyle. |
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CJ Bradley collects the corals from her experiment, as the Pisces V looks on. Photo: R.L. Pyle. |
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Ross Langston (left) watches CJ Bradley (right) as she collects her coral samples in front of the Pisces V. A school of 'opelu (Decapterus) swims by overhead. Photo: R.L. Pyle. |
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Ross Langston (left) and CJ Bradley (right) leave the bottom and Pisces V to begin the long decompression back to the surface. Photo: R.L. Pyle. |
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Safety diver Holly Bolick descends to join us during the decompression. Photo: R.L. Pyle. |
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Ross Langston kicks back on the decompression line. The reason he's wearing a hat is not to be silly, but because it's actually possible to get a sunburn underwater under bright tropical sunlight, during the shallowest decompression stop. Photo: R.L. Pyle. |