# Navigational Risk Assessment in Offshore Wind Farms Using Spatial Ship Domain Models
## 4 Discussion
Such phenomena have been observed and documented in the North Sea and UK sectors, particularly in connection with crew transfer vessels and service operations. While this study focuses on fixed-bottom turbines (monopile foundations), it is worth noting that floating offshore wind structures, increasingly deployed in deeper waters, pose different navigational risks due to their motoring systems, anchor lines, and dynamic motion in response to the sea state. These differences require distinct safety buffers and vessel exclusion zones. Incorporating such operational constraints and sensor-related limitations into future \(\mathrm{R_{N}}\) models or navigational guidelines would improve the practical applicability of spatial risk assessments in OWF areas. In practical terms, the Rutkowski 3D model offers valuable input for maritime authorities, pilot organizations, and port operators engaged in offshore spatial planning. Its output can support the identification of safe navigation corridors, service vessel access routes, and exclusion zones tailored to the vessel type, maneuvering capacity, and prevailing environmental conditions. These results are aligned with international safety standards and can serve as a tool for translating general PIANC and SOLAS guidelines into risk-based, location-specific navigation policies. This study offers several key contributions to the current body of research on navigational safety in offshore wind farm areas. First, in contrast to most previous works that rely solely on two-dimensional ship domain models [16; 17; 21], this analysis applies a spatially explicit 3D ship domain model that accounts not only for vessel maneuvering characteristics but also for vertical risk factors such as under-keel clearance (UKC) and over-head clearance (OHC). Second, the study introduces a comparative framework by evaluating navigational risk indicators (\(\mathrm{R_{N}}\)) using three distinct modeling approaches (PIANC, Coldwell 2D, Rutkowski 3D) across different vessel types and environmental scenarios, which has not been systematically carried out in the existing literature. Third, by integrating model-based simulation data with realistic traffic and environmental parameters, this paper provides an operationally useful tool for offshore spatial planners and maritime authorities. The enhanced \(\mathrm{R_{N}}\) methodology and its application to three representative vessels offer a practical benchmark for developing vessel-specific access rules and corridor designs for OWF areas in the Baltic Sea and beyond. In summary, this study confirms that multidimensional navigational risk assessment models are essential for evaluating the feasibility of vessel movement within OWF areas. The 3D spatial model, which includes horizontal and vertical safety margins and accounts for vessel-specific dynamics, provides a reliable and operationally meaningful framework. Its implementation can enhance the coexistence of offshore renewable infrastructure with existing maritime traffic and support more adaptive and evidence-based regulatory practices. Furthermore, these results offer a practical foundation for formulating vessel-specific transit guidelines and safety buffer zones within OWF layouts, thereby improving navigational safety and strengthening offshore spatial planning frameworks.