What makes an experience sustainable? Can polar cruise tourism in the High Arctic ever be sustainable? If so, under what conditions? These questions guide this report as it explores tensions embedded in the concept of ‘sustainable polar cruise tourism’. These matters are of particular importance in Svalbard, with a rapidly developing tourism sector being an important part of the Svalbard economy. The report is based on a participatory workshop held on-board a recent expedition to the Svalbard archipelago, the so-called SEES expedition (the Scientific Expedition Edgeøya Svalbard). Conducted as a combined scientific and touristic expedition, the SEES expedition offers opportunity to explore the meaning(s) of sustainability among environmentally aware visitors representing key actor groups on Svalbard. The purpose of the report is thus to contribute to ongoing conversations on the paradoxes of sustainable polar tourism by sharing experiences and perspectives on what sustainability can mean from a passenger point of view.