At the Fraunhofer Institute for Computer Graphics an interactive system for the visualization of environmental data called VISMAR, has been developed. This system allows both the interactive design and production of maps of any geographical region and the visualization of marine environmental data in that geographical context using different kinds of 2D- and 3D-methods for scientific visualization. The methods of scientific visualization offered by VISMAR enable the graphical supported analysis of environmental data for administrative as well as for scientific purposes. The system has been implemented as an open and extendable system for UNIX-workstations on the base of X-Windows, OSF/Motif and PV~WAVE. This article gives a brief summary of the main features of VISMAR and shows its usability for the solution of tasks for environment monitoring.