Scéir Dubh: translates as “Black Reef” and is located in an ideal spot where partially fresh water from Trawbreaga Bay meets the tidal waters that work their way around the entire Irish coast as a “Counter Tide”. This causes a minor whirlpool effect that when combined with semi-fresh water was a gathering point for Wild Atlantic Salmon. (A counter tide is when the main tide is for instance going west, a tidal sweep begins to move along the rocks in an easterly direction, gradually widening and expanding seawards as the west-going tide weakens as slack-water or the turn of the tide approaches).