Electronic upgrades will be made to a suite of shared-use ocean bottom seismometers (OBS) that are used in long-term deployments on the sea floor. Scripps Institution of Oceanography maintains a number of OBS instruments to record seafloor seismic activity for periods of up to a month at high data rates. The upgrade will allow the instruments to record data continuously for a six-month period. This new capability will be accomplished through the addition of a second digital audio tape recorder, rearrangement of analog circuitry, and the addition of new batteries. Once upgraded, the instruments will be capable of long-term deployments required for experiments such as those proposed in the RIDGE Global Change research program.