The tidal atlas is a mapping of the movement of the water in Dublin Bay as the tide rises and falls.  The colours and arrows on the chart represent the strength and direction of the water movement.  Spring tides occur at both Full Moon and New Moon which is every 14 days in the 28 day lunar cycle and represent the strongest tides. The neap tides occur in between Full moon and New Moon and represent weaker tidal flows where the tide comes in and goes out to a lesser extent than the spring tides. 

Dublin Bay Tidal Atlas – Springs

Dublin Bay Tidal Atlas – Neaps