Mullaghmore Head Swell Window
County Sligo, Ireland · part of the Mullaghmore Head spot guide
- Swell window (from)
- 240°–340° (WSW–NNW)
- Best direction
- ~295° (WNW)
- Period sweet spot
- 15–20 s
- Open-ocean height (Hs)
- 13–26 ft
- Resulting faces
- 8–40 ft
Open-ocean vs. the face: the heights on buoys and forecast models are significant wave height (Hs) in deep water. What you ride is the breaking face, which depends on period, direction and this break's bathymetry — that's why the two rows above differ. PierMonkey's spot ratings already do this conversion for you.
The window runs from southwest through north, with the sweet spot true west-to-northwest around 280–310° matching the headland’s aspect straight into the open Atlantic. Period matters as much as height: it wants long groundswell of roughly 15-to-20 seconds and up, and short-period wind swell will not engage the reef even at big height.
The open-ocean height feeding it is far smaller than the wave you see — a rideable face runs several times the offshore reading. The bands here separate the two: a solid big day comes off roughly a 13-to-18-foot open-ocean height at long period, an XXL day off 20-foot-plus. Read the alert threshold as open-ocean height, not the face.