Governments worldwide are intensifying efforts to address escalating flood risks exacerbated by climate change. Central to this endeavor is the implementation of institutional frameworks, such as public policies, aimed at mitigating, planning for, responding to, and recovering from flood events. However, the effectiveness of these institutions relies heavily on their practical application. This study delves into the institutional landscape of flood risk management (FRM) through a comprehensive case study in Sint Maarten, a Caribbean island. Specifically, we scrutinize the degree of institutional compliance, focusing on the alignment between formally advised policies (institutions-in-form) and their informal adoption in practice (institutions-in-use). Employing Institutional Network Analysis (INA), we explore discrepancies between these two dimensions across the various phases of FRM (response, recovery, mitigation, and preparation). Our findings reveal that institutional compliance varies significantly across the FRM phases, with mitigation presenting the most pronounced challenges. Notably, the discrepancies are more prevalent among those tasked with implementing the policies rather than the targeted property owners. Generally speaking, the transition of institutions from mere forms to actionable rules is often hindered by established or emerging practices diverging from prescribed directives.