Tourists often fail to follow through with their sustainable behaviour intentions. This lack of compliance can only truly be explored by observing their actions when immersed in the context of a vacation. A holistic case study was conducted by monitoring a group of young consumers on a cruise. Five quantitative and qualitative methods (i.e. baggage audit, participant observation, photo elicitation, diary and introspection) have been employed to collect rich and diverse data on young tourists’ behaviours. This allowed to complement behavioural measures with young tourist lived experiences, overcoming the limitations of self-reported measures. The findings suggest that young tourists do not always behave sustainably while on a cruise, and they morally disengage from such behaviours to deal with those choices. Eleven macro-categories of (un)sustainable behaviours have been observed and identified before, during and after the cruise. The findings also highlight the emergence of four coping mechanisms that allow young tourists to disengage from the unsustainable behaviour and overcome the discrepancy between their pro-environmental values and behaviours. Managers in the tourism industry need to find communication strategies that appeal to the sense of responsibility of a tourist even before the journey and highlight a hedonic dimension to sustainable behaviours.