So far we have explored two ships. Both ROV launches went off without a hitch, performed as methodically and gracefully, as Tito (Chief Pilot of the ROV) put it, “as a ballet.” The ROV Jason goes in first. Sizing up at about 3 meters long, 2 meters high, 2 meters in width, and weighing in at just over 9,000 pounds, the ROV is big but not necessarily intimidating. Still, it is a magnificent piece of equipment, intelligently assembled and maintained to allow a crew on the ship to control its every move. Jason was lifted by a large crane (a powerful piece of machinery itself) up and over the side of the ship and slowly lowered into the water while the crew neatly fed the connected fiberoptic communication cable across the deck. An extremely large A-frame then lowered Medea off the stern of the ship. Medea is a little smaller than Jason, about 2 m x 1.5 m x 1 m and 3,000 pounds, and acts as a shock absorber and extra eyes for Jason. From here on out the action would occur inside the ROV van, where Jason and Medea are piloted and monitored.
Based on previous bottom scanning sonar data, we had a pretty good idea of where the shipwrecks were located. We were in shallower water, so even at the slow diving speeds of Jason (~30 m/min) we reached the wrecks relatively quickly. Everyone watches when work allows. For those who are outside of the ROV van there is a large screen monitor with six different feeds set up in the science lab. Five of the frames show live video, three cameras from Jason and two cameras from Medea, while the sixth frame shows our position relative to previously mapped out ocean floor data. After going in the water, the main camera for the scientific crew (the science camera, located on the front right of Jason) is just aqua blue, illuminated in the center by Jason’s lights. We had clear waters in comparison to previous dives, and as we descended we saw a rain of particulate matter in the water column as well as the occasional dogfish swim by. As we neared a site, more and more dogfish would begin to appear within the view of Jason’s cameras. This was a good indicator of our close proximity to the wreck. Finally, a faint structure would appear just within the beam of Jason’s lights that looked somewhat out of place in the marine environment. The structure would slowly form into an observable manmade creation. We had reached the ship.
During a dive, the first part of the mission was spent analyzing the perimeter of the wreck to determine the condition of the ship and any observable structures. The first ship we dove on may have appeared to me a tangled mess but was actually in fine condition, and our chief scientists were able to observe many key structures. The second ship was a little different. Due in part to its structure and manner of sinking, it had settled to the bottom in an upside-down position. This provided a somewhat different aspect of the ship’s architecture. In this position we were able to identify the rudders and propeller shafts on the stern of the ship.
After reconnaissance, a considerable amount of time is spent taking pictures of the wreckage from a top-down view using Jason’s bottom camera. These images are used to create a high detail mosaic of the shipwreck. This final production gives us a complete view of the current condition and structure of the ship.
Time is also spent analyzing and sampling the biota of the wreckage. While these ships were once grand examples of human power and our capability to construct and create, they are now an example of underwater life’s ability to adapt and overtake a ‘foreign’ habitat. These now fractured vessels are alive with the marine organisms that have found a suitable home on their surfaces and in their nooks and crannies. In and around the ship we have seen numerous dogfish and tilefish. Attached to the ship itself are several types of organisms including anemones, bivalves, hydroids, and sea stars. Several of these specimens have been collected and prepared for more analyses following the cruise.
Much has been accomplished with the completion of these two dives. What we have seen and sampled will continue to be analyzed and is a great addition to our research goals. This is not the end though….