Environmental monitoring is getting more in focus of attention than ever before. New national and international standards for the observation of the water quality in lakes, rivers and oceans are getting challenging to fulfil for public authorities and industry. One solution is the use of automated sensors, which monitors chemical compounds in high resolution during long-term series. Beside the more accurate data set obtained by sensors, water samples don’t need to be returned to a central laboratory which safe personal and lab costs. The novel UWMS of SubSeaSpec measures nearly all gases and volatile organic compounds (up to m/z 200) simultaneously, in real-time and in situ and is a great tool for the observation of the water quality. The UWMS could also detect water contamination by e.g VOCs or BTEX at low level (ppb) which could help to establish an accurate risk management for several applications.