dutch ebb low tide

activity barrage barrier below blue climate clouds cloudy construct construction control current danger dangerous delta dikes dutch dykes ebb ebbtide ecological ecology environment europe flood floods furious high holiday holland kats landscape leisure level low lowland marine natural nature netherlands oosterschelde peaceful polder prevention protect protection quiet relaxing rocks rocky sail sailing sand sandy scenery scenic sea seadefence seasurface seawall seawater ship sky stones storm stormy sunny surface tidal tide touristic tranquil water watermanagement waterside wetlands wind zealand