Solid-state microelectrodes have been used in situ in Raritan Bay, NJ to measure pore water profiles of dissolved O2, Mn, Fe, and sulfide at (sub)millimeter resolution by voltammetric techniques. The voltammetric sensor was positioned with microprofiling instrumentation mounted on a small remote operated vehicle (ROV). This instrumentation and the sensor were controlled and monitored in real time from a research vessel anchored at the study site. The voltammetric analyzer was connected to the electrodes of the voltammetric cell with a 30 m cable which also bridged receiver-transmitter transducers to ensure signal quality along the cable. Single analyte O2, pH, and resistivity microsensors were operated alongside the voltammetric sensor. We report on the technology of the system and the concentration changes of redox species observed from 2 to 3 cm above to approximately 4 cm below the sediment−water interface during three deployments. O2 measurements from both Clark and voltammetric electrodes were in exc...