Dublin Bay is subject to tide and although the speed of the current is not excessive, it is often of tactical importance. The current flow is simple and well documented.
The tide turns at Dún Laoghaire harbour approx 4 minutes before high/low water at the North Wall in Dublin Port. The main flow in the Irish Sea is to flood North and ebb South, and the complex streams within the bay also follow this basic principal.
The depth of water in the racing area is 5-12 metres.