The aim of this study was to investigate students' understanding of the Gulf Stream as a geographical phenomenon and in relation to geospatial conceptualizations focusing on the geographical concepts of location, distribution and interaction. Data consists of 134 responses from 12-13-year-old students who completed an assignment in the Swedish national test in geography (2013). The responses were analyzed using thematic analysis. Data was complemented with interviews in 2017. Results show that many students hold alternative conceptions of the Gulf Stream in relation to geographical concepts, which implies that instruction should focus on students' geographical contextual understanding, including map-reasoning skills.