Current interest in ocean acidification has led to development and deployment of an underway pCO2-pH system. Built in the lab of Dr. Todd Martz at Scripps Oceanography for LTER, the system is installed by CALCOFI on our quarterly cruises. The system is comprised of a Sunburst Sensors SuperCO2 system for pCO2, a Durafet III pH electrode analyzer used to measure pH (via Honeywell UDA2182), and a Seabird SBE45 thermosalinograph. Output data from these systems is merged in real time with Lat/Long position on a data hub consisting of a PC running LabView software. Using the ship's uncontaminated seawater feed from ~3m, near-surface data are acquired 7/24 during the cruise.