The pictures below shows a NW swell hitting the North Shore, Hawaii. Offshore swells are modified by the offshore reefs and channels within the reef systems well before they reach the famous breaks like Pipeline and Sunset Beach along the North Shore. The pictures show the detail in the offshore bathymetry included in the modeling, and the importance of the bathymetry in defining the surfing spots; something not taken into account by other marine forecasters that provide offshore marine conditions.