Detailed maps of the seabed, including substrate classification maps and comprehensive habitat maps, are used for a wide range of environmental, scientific and economic maritime applications. They provide a basic concept for ocean and coastal management, and serve as a cornerstone of national and international nature-conservation policy. Fundamental to seabed mapping are acoustic remote-sensing technologies which include singlebeam, multibeam and sidescan sonars along with interferometric and synthetic-aperture sonars. These are deployed on various platforms including manned/unmanned surface and underwater vessels. In relatively shallow and transparent waters optical methods such as aircraft and satellite-based remote sensing and lidar are employed with increasing success. Innovative processing and classification software, image analysis, machine and deep-learning applications are advancing developments in seabed-recognition techniques. The application of which increases the resolution and confidence in the resulting environmental maps produced. This session will provide insights into new developments, methods, and results in the field of seabed mapping and classification; showcasing a range of applications for these decisive datasets.