The Mayotte volcanological and seismological monitoring network (REVOSIMA) was created in response to the sub-marine eruption that started in May 2018. Composed by IPGP, BRGM, IFREMER and CNRS, its main missions are 1) to observe and study volcanic phenomena through real-time volcano monitoring, 2) to conduct research programs, and 3) to communicate, disseminate and inform authorities and civil society. These real-time observations and research can contribute to the prevention, and mitigation of seismic and volcanic risks. The main objective is to collect geological, geophysical and geochemical data over long periods of time to improve the understanding and modeling of volcanic processes at active volcanoes, to allow the systematic elaboration of long-term multi-parameters databases available to the scientific community, and to inform the authorities in charge of civil protection of any change in the volcano activity and after periods of local and regionally felt earthquakes.