Maritime service vessel in the aquaculture industry represent a noticeable source of emission with service boats and well boats estimating around 500 000 to 750 000 tonnes of CO2 in 2021. Hybrid vessels are also becoming more commonly used as service vessels, and play into the future of decreasing diesel-fuel emissions by leveraging increasingly better batteries. At the same time, maritime service vessel operations are hard to plan due to dynamic conditions like weather and changes in missions. Therefore the need to see estimates of route options could help operational planning of routing for service vessels both for causing less emission and for estimating optimal routes. This thesis explores how a route estimation decision support systems (DSS) can be designed for hybrid service vessels, with a focus on how information density and eco-feedback features play into planning decisions. The project collected insight from researchers, experts working with service vessel planning, and observations from a field trip to a working service vessel. This insight was used in the design phase to design two prototypes with different information density, which were evaluated with five industryrelevant participants. Two routes was purposed to the participants, one with higher emission and higher task efficiency and one with less emission and less task completion. The evaluation collected qualitative insight as well as task completion time data and System Usability Scale (SUS) data. The results showed that all participants preferred the prototype with higher information density. However, the prototype with less information density scored higher in the SUS evaluation and participants used less time to complete tasks. The eco-feedback features were successful in conveying the emission costs of the routes, although all participants unanimously chose the less environmentally friendly route, siting higher task efficiency. Some importaint user needs in the DSS was estimations regarding tasks schedule, energy consumption metrics, cost metrics, emission metrics, information about shore charging and map visualizations with weather data. These results suggest that a route estimation DSS which feature important KPIs has value and can help operational planners in the to the industry to better manage their service vessel fleet.