Visualization and integration of the marine spatial data collected by various marine sensors and sources is an important factor in the context of marine environment sensing and monitoring. Several approaches and techniques of measurements are available to achieve this purpose including direct sampling, airborne and satellite imagery, and underwater acoustics. The paper briefly describes the state-of-the art marine GIS system developed in the Department of Geoinformatics of Gdansk University of Technology, Poland. The proposed system is able to integrate many different types of marine data, especially those acquired by various acoustic sensors like multibeam sonar (MBSS), echosounder and side scan sonars (SSS), and other external sensors such as satellite data receiver, radar, or automated identification of ships (AIS) data analyzer. Instantaneous 2D and 3D visualization is provided by the two components of the system: GeoServer web-based module and a standalone application basing on ESRI ArcGIS Engine solutions.