Today was filled with frustration followed by incredible success. Dive 523 began at the normal launch time of 0630 into dead calm seas and clear skies. A brief dunk in the water and the vehicle came back on deck due to an electrical problem. This was soon fixed—it was a cable burned by the hot vent fluids! Back into the water with high hopes and expectations—but only for another 30 minutes until the vehicle was once again recovered. The acoustic modem that lets the pilot prevent twists in the tether was not communicating. This had been a problem from the beginning, but each previous time the pilots had been successful in resolving the communication problems. Unfortunately, this was not the case today. Yet another dive, and the pilots decided to replace the new modem with the older compass. While the pilots labored on the vehicle, the scientists napped, looked at samples, and caught up on email and paperwork. 

Buck and new pilot Jim Cohen sat at the controls. Jim got about three hours of flying practice while we searched for the missing elevator basket. Our first elevator attempt ended in disaster when the basket (carrying rock and water samples) came off during recovery. We spent 90 minutes searching the path of the elevator tonight, but only found the drop weights. What we did find was a new hydrothermal site with white microbial mat encroaching upon a lineament of tall spires on a small hill. We named this new site Cathedral Hill (see right) and left an acoustic beacon so that we could find this again tomorrow. 

Onward to the Busted Mushroom Site to collect fluid and check on our first thermocouple array. The fluids at the Busted Mushroom Site had done the trick! There was a new chimney neatly enclosing over half of the thermal array (see left). We decided to let this grow for another day—let’s not press our luck…However, this decision meant that the pilots (now Paul Tucker on the manipulator and Buck Reynolds flying the ROV) would have to sample the overlying chimney without toppling over the new structure. 

We held our breath as the water bottles were each lifted into the smoking orifice. The ICL-controlled fluid samplers require that the manipulator hold them so that their thin nozzles are delicately perched steadily within the highest temperature fluids for at least two minutes. Notwithstanding the late night hours, the light touch of the pilots did the trick (see right). 

The last requirement was to install the long wand for the Osmosampler and the Hobo into the same chimney without disturbing the thermocouple array seen on the bottom left in the photograph (see below). The pilots accomplished all of this work requiring intense concentration in less than 2 hours, and then we all shuffled off to get some sleep.

Debra Stakes