The objective of this thesis report is to establish a sound body of knowledge about real-time risk analysis, and to apply it to build a real-time risk analysis model for autonomous ships. For this purpose, the Sundbåten autonomous passenger ferry project which is currently under way is taken as a case-study. Here the mission is to develop a real-time risk model which is capable of warning the captain to take the ship’s control when its autonomous system is incapable to do so.