Storm Xynthia (2010) brought to the fore marine submersion as a great concern to French authorities and communities. This storm illustrates how a single major event can have long lasting effects on climate risk management. To discern this effect, we conduct two studies analysing the emergence and evolution of concerns related to marine submersion in French national and regional newspapers prior to and after the storm (2005-2018). In Study 1, we examine trends in issue coverage and how ‘marine submersion’ was appropriated by French media discourse over the selected period, identifying and segmenting specific topical sequences. In Study 2, a computer-assisted content analysis of 260 articles highlights a dichotomy of themes before and after Storm Xynthia. Articles published prior to Xynthia (2005-2009) warned of marine submersion among the expected impacts of climate change. Those published just after Xynthia (2010-2013) present highly structured and technical descriptions of national risk management policies. In recent years (2014-2018), articles focus on local stakeholders’ challenge to national risk management policies, described as too far removed from local dynamics. Our studies reveal the emergence and amplification, via public debate in French newspaper media, of ‘marine submersion’ as a hazard, and the objectification of the risk through Storm Xynthia.