This proposal addresses the need for advanced chemical sensing in the ocean environment by developing a new mass spectrometer and integrating the instrument into the operation of an autonomous underwater vehicle (AUV). The mass spectrometer's sampling capabilities and energy requirements present an opportunity for an intelligent integration scheme to increase the instrument's scientific capability. Through feedback from other onboard sensors and vehicle navigation interdependent sensing strategies will make autonomous data-driven decisions, re-tasking the sensing and guidance based on estimation of the environmental state. These techniques will increase the overall efficiency of deep ocean exploration in dynamic and complex environments such as the chemical processes found in both cold and hydrothermal bottom seeps. The engineering research necessary to realize the capabilities of an integrated mass spectrometer operating from an AUV include: development of an integrated mass spectrometer specifically designed for integration into the hardware and software of an existing AUV; development of an environmental representation for assimilating networked oceanographic sensor data, mass spectrometer data, and vehicle navigation in real-time; development of a mission specification process for specifying event driven surveys and analyzing the performance and robustness of these missions; combining the above components into a control system for a data-driven AUV survey. The primary scientific driver for this work is the study of seafloor vents and seeps.