Vessel Traffic Service (VTS) is a shore-side service implemented by a "Competent Authority to improve the safety and efficiency of vessel traffic and to protect the environment". It is a service that operates through VTS centers, from which VTS operators monitor traffic, assist in navigational matters and provide information to all ships in a designated area. As VTS is provided by operators located on shore, they usually make use of several decision support systems to be able to monitor the traffic and to provide information to the vessels. Although several new tools and approaches have been introduced in the VTS domain, there is still room for improvements. This paper summarizes the results from three studies conducted within the EfficienSea project to approach user needs for dynamic risk management in the VTS domain. Data was collected by conducting study visits and observations at VTS centers, a focus group interview as well as several semi-structured interviews. The paper summarizes the results and presents technical and organizational user needs for dynamic risk management within the VTS domain.