Our event will touch upon the critical issue of noise emanating from shipping activities, with a particular focus on the adverse impacts of propeller cavitation on maritime ecosystems. Additionally, we expect to touch upon URN class notation and the history of the IMO guidelines on URN, and possible future legislation. We will also explore advancements in mathematics and physics that may be driving solutions towards quieter ship propellers. The event mainly addressess to ship owners, authorities, and ship consultants. This seminar has come about as part of our ongoing partnership between Danish Shipping, the Danish Maritime Authority, and the Danish Ministry of the Environment.