Sea Crossings
State of Sea until 1900 Tuesday 16 September 2025
Dublin - Holyhead
Moderate to rough, increasing rough to very rough by Monday morning. Decreasing moderate to rough by Monday afternoon and moderate by Tuesday morning. Further decreasing slight to moderate by Tuesday evening.
Rosslare - South Wales
Rough, increasing very rough Sunday evening and high at times Sunday night and Monday morning. Decreasing rough Monday night and moderate through Tuesday morning.
Cork - South Wales
Very rough, increasing high at times Sunday night and Monday morning. Decreasing rough Monday night and moderate through Tuesday morning.
Rosslare - France
Very rough. Increasing very rough to high Sunday night. Decreasing very rough Monday evening. Further decreasing very rough on Monday night and decreasing moderate to rough Tuesday morning.
Cork - France
Very rough. Increasing very rough to high Sunday night. Decreasing very rough Monday evening. Further decreasing very rough on Monday night and decreasing moderate to rough Tuesday morning.
Rosslare - Spain
Rough to very rough, increasing very rough to high Sunday night. Decreasing rough to very rough Monday evening and mostly rough Tuesday morning. Decreasing moderate in northern areas later.
Legend
| Sea Crossings | WMO Code | Wave height | Characteristics |
|---|---|---|---|
| 0 | 0 metres (0 ft) | Calm (glassy) | |
| 1 | 0 to 0.1 metres (0.00 to 0.33 ft) | Calm (rippled) | |
| 2 | 0.1 to 0.5 metres (3.9 in to 1 ft 7.7 in) | Smooth (wavelets) | |
| 3 | 0.5 to 1.25 metres (1 ft 8 in to 4 ft 1 in) | Slight | |
| 4 | 1.25 to 2.5 metres (4 ft 1 in to 8 ft 2 in) | Moderate | |
| 5 | 2.5 to 4 metres (8 ft 2 in to 13 ft 1 in) | Rough | |
| 6 | 4 to 6 metres (13 to 20 ft) | Very rough | |
| 7 | 6 to 9 metres (20 to 30 ft) | High | |
| 8 | 9 to 14 metres (30 to 46 ft) | Very high | |
| 9 | Over 14 metres (46 ft) | Phenomenal |
