08/17/03 - First dives
Last night we enjoyed dinner and then had a submersible safety briefing in the lounge. This included information for the folks who will be diving as well as the safety guidelines for the people observing the sub launch and recovery. After that we met the captain who went over the safety procedures for the ship. Doni Angell, Educator at Sea, modeled the immersion suit. This is frequently called the "Gumby Suit" because you look like an orange "Gumby" character when you are in it. We also learned about what to do in case of an emergency, such as fire or man overboard. After these meetings we finished setting up all of the computers we use during the trip to help us keep track of data, collect digital photos and create maps. At the moment there are 9 computers set up in the dry lab!
We steamed to our target destination and arrived about 2 a.m. The night crew got up to help with "transects." Transects are where we take the ship back and forth and back and forth over a specific location. We use the readings from the fathometer (which tells depth) to determine the best place to send down the submersible. After choosing our ideal spot, we then put a Neuston net over the starboard side to try to collect surface samples from the same area. The only things we caught were some sargassum, a type of brown algae, a six-inch fish that appears to be a species of jack, a miniscule jelly and an equally tiny crab.
At 8 a.m. we launched the first sub dive with Andrea Quattrini with the North Carolina crew in the bow and Ken Sulak of USGS in the stern. The crew calculated the location of the launch based on the strength and direction of the current below the ship. The sub descends at an angle because the current will push it forward. It can be quite a tricky math problem to calculate how far forward the sub will be by the time it reaches the bottom. This time the seas fooled us and the surface currents were much stronger than the deep currents. The sub arrived short of its intended site. Luckily the scientists on board were still able to use the new digital camera to take pictures of the fish and corals as well as other invertebrates found at the bottom. They returned to the surface with a galatheid crab.
As soon as the sub is back on deck it gets plugged into the ship's system so that the battery can recharge. It takes nearly four hours for it to charge completely, so we enjoy lunch and do some other tasks such as copying videotapes from the dive. We also used Sharpie permanent markers to write on Styrofoam cups. These cups will be attached to the outside of the sub in a mesh bag. When they come back to the surface they will be much smaller than they were, due to the intense pressure. We did so many cups that we will have to send them down in several batches.
We chose a new site, based on the current observations from the morning dive, to launch the sub in the afternoon with Martha Nizinski (National Marine Fisheries) in the bow and Allen Brooks (USGS) in the stern.
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