This paper aims to share relevant findings regarding trust towards unmanned vessels during decision-making processes. The methodological approach used questionnaires and six simulated cases, where we conducted an experimental study to assess how the decisions made by participants change when interacting with unmanned vessels. The main results showed no evidence of a relationship between Automated Vessel confidence and age or expertise level. However, we found a tendency to adjust the decision when encountering an Automated Vessel or the possibility of being one. Among the possible practical implications, we have an improved understanding of how the perceived status of the encountered vessels affects the pilot’s trust and decision-making. Recognising that trust in automation is an influential critical factor, we adopted existing framework models to evaluate the participants’ perceptions of Maritime Autonomous Surface Ships (MASS) as classified by the International Maritime Organization.