The station was visited on Tuesday, July 7th and Wednesday, July 8th, 2009, by a team consisting of Dr. Derek Manzello (NOAA/AOML in Miami, FL), Gary Trommer, Sam Halvorsen (both of Dive Experience in Christiansted, St. Croix) and myself, Mike Jankulak (University of Miami).
Our primary goal was to repair the satellite transmissions system. While we were there, we also planned to replace all instruments that are on 1-year deployment schedules. This included the light sensors (Surface, Shallow and Deep), Conductivity-Temperature-Depth sensors (or CTDs, Shallow and Deep), Vaisala "Weather Transmitter" (or WXT), Anemometer and Electronic Compass.
The primary objective was met. The external connection point of the transmitter's satellite antenna and its cable was found to be corroded, and both the antenna and cable were replaced. The replacement cable was wrapped with tape at its attachment point to better protect it. Following this work, the station is once again transmitting.
The equipment replacement was only partially successful. The new anemometer did not function properly in field tests, so the old anemometer/compass were reinstalled for the time being. However, the old anemometer/compass are not longer operational following their removal and reinstallation. Also, the standalone air temperature sensor started malfunctioning at some time during this visit. All three instruments (anemometer, compass and air temperature sensor) should be replaced at the next opportunity.
Also, at the end of our work we found that the "Deep" CTD was not communicating properly with the station. This is probably either a loose wire in the instrument's plug (at the top of the pylon, inside the "brain" chamber) or a bad connection within the "brain" package itself. The serial-port units were both looking rusty, and may also be a problem. There is currently no sign of damage to the instrument's underwater cable, either at the waterline or lower down, but there's also a small possibility that this cable is bad. The instrument itself was retrieved to the boat and was demonstrated to be fully operational. It was manually programmed and reinstalled. It will continue to operate normally and store its data internally for later retrieval. It is not known whether the CTD is being supplied with power from the station or not. If it is, it could run for indefinite periods of time. If the power connections are also broken, the CTD might only run for a few months before exhausting its local battery power.
Due to logistics problems (the boat was not available for work either Wednesday afternoon or Thursday morning), work was brought to a halt at this point. However, this station should be visited again, and sooner than its regular 1-year equipment replacement schedule. The next visit should address the problems with the compass, anemometer, air temperature sensor and Deep CTD. It's also been suggested that we reinstall the rubber covering that was protecting the underwater cables at the waterline.
-- Mike Jankulak