Refraction may redirect waves from multiple directions into a harbour: a case study in the Gulf of Riga, eastern Baltic Sea

We analyse the impact of bathymetry on the propagation direction of wind waves near the Port of Ringsu on the island of Ruhnu in the central part of the Gulf of Riga (Gulf of Livonia). Waves propagating towards this port are systematically redirected by underwater features. On most occasions the main direction of the refracted saturated wave fields is towards the harbour entrance. This shows that the port entrance needs a complicated set of breakwaters to cope with wind generated waves from most directions.