On September 1, 2001, a vertical linear array (VLA) of four hydrophones, and associated electronics, was installed on the summit of Pioneer Seamount, and data acquisition equipment at the Pillar Point Air Force Station started relaying the data to an archiving center at PMEL in Newport, Oregon. Since then, the observatory has been actively collecting data except for off-line periods imposed by equipment failures. The chart below shows which days were active, partially active, or off line. As of September 24, 2002, the Observatory is off line due to a cable failure. Between September 1, 2001, and September 24, 2002, the Observatory was on line 56% of the time (217.5 days out of 389 active).