Offshore geohazards including earthquakes, mass gravity flows, volcanic eruptions, and tsunamis are capable of significant loss of human life and economic disruption. Recent advances in geophysical imaging, scientific ocean drilling, and seafloor instrumentation have increased the understanding of offshore geohazards. However significant knowledge gaps remain in understanding the timing and interplay of geological processes at the origin of geohazards. For example, high-latitude regions are experiencing dynamic changes in response to global warming that can lead to geohazards but are complicated to predict. Forecasting and risk assessments including probabilistic approaches are complex given the uncertainties involved and therefore geohazard quantification is poorly constrained. The sedimentary record of past offshore and coastal hazardous events is often well preserved in marine and lacustrine environments and can be investigated in detail with high-resolution geological and geophysical tools. We welcome contributions that highlight new results, methodologies, monitoring techniques, and lessons learned from case studies in areas of paleoseismology, submarine landslides and sediment flows, tsunami generation, and volcanic processes. We invite contributions from all margins and environments, including lakes. The aim of this session is to bring together the scientific community, marine industry, and governmental agencies involved in geohazard research and management to promote cooperation and better understanding of offshore geohazards.