Marine radar systems are a core technical instrument for collision avoidance in shipping and an indispensable decision-making aid for navigators on the ship’s bridge in limited visibility conditions at sea, in straits, and harbors. While electromagnetic attacks against radars can be carried out externally, primarily by military actors, research has recently shown that marine radar is also vulnerable to attacks from cyberspace. These can be carried out internally, less “loudly”, and with significantly less effort and know-how, thus posing a general threat to the shipping industry, the global maritime transport system, and world trade. Based on cyberattacks discussed in the scientific community and a simulation environment for marine radar systems, we investigate in this work to which extent existing Intrusion Detection System (IDS) solutions can secure vessels’ radar systems, how effective their detection capability is, and where their limits lie. From this, we derive a research gap for radar-specific methods and present the first two approaches in that direction. Thus, we pave the way for necessary future developments of anomaly detection specific for marine navigation radars.