Human state monitoring in maritime training – The On Watch case

In safety-critical domains, training is a socio-technical infrastructure (spaces, interfaces, procedures, and preparation, execution, and final review phases) that supports learning and the development of a safety culture. From this perspective, the paper proposes an operational framework for Designer-in-the-Loop (DITL) to introduce Human State Monitoring Systems (HSMS) into maritime training, making the trade-offs between digital innovation and surveillance-related risks, such as bias and inequality, explicit and verifiable. Within this framework, On Watch is adopted as a case study, enabling operational testing in a concrete application context by integrating multimodal signals and translating them into non-prescriptive probabilistic indicators, without rankings or automated decision-making, in support of the final review phase. A pilot experiment, structured across three contexts – ECDIS, cooperative bridge, and interview – evaluates feasibility, usefulness, and acceptability through replicable technical-operational and socio-distributive key performance indicators.