14/05/2026
How quickly things change.
Our Friday tour to Isle of May is cancelled due to forecast high waves and sea swell.
That's not news we like to bring. So here’s more detail.
Most of our passengers travel internationally to visit the Isle of May National Nature Reserve so it’s a great disappointment if the weather causes cancellation.
It’s perplexing to stand ashore in reasonable weather and find that your boat tour has been cancelled. Often, what seems OK weather on land doesn’t give any indication of sea conditions.
So, here’s an insight into tomorrow's weather forecasts – many sources are free so you can check them out.
Tour scheduled : Friday dep. Dunbar 1015, rtn. c1600hrs.
Met Office: we monitor synoptic charts days in advance, watching for weather fronts, directions and long-range changes. Low pressure to E of UK causing winds from N.
Windguru: Friday 1000, wind NNW 16knts gusting 21knts – so that’s OK. Wave height and swell NE, 2metres - not OK. The Pro version gives us hourly forecasts at specific locations (see photo). Wave height means a definite cancellation. We have bespoke modelling forecasts for both the Isle of May and for Dunbar. The forecast for Dunbar is for wind from the NW, 2.4m waves and swell from the NE and only dropping to 2m later in the day.
Windy.com: Waves 2m @ 20 degrees with 9 second interval shifting to 2m at 30 degrees with 10 second interval.
The Centre for Environment, Fisheries & Aquaculture Science (CEFAS). This organisation has weather monitoring ’WaveNet’ buoys in the sea all around Britain. One is located near the Isle of May. It’s publicly available information here: https://wavenet.cefas.co.uk/details/FORTHWN/INT
Wavenet forecasts a 2m swell at 0500 hrs dropping by 30 centimetres to 1.7m by 1700hrs.
Many people watch the TV for weather forecast or use the BBC Weather app: Friday- light cloud and a moderate breeze of about 17 mph. So, just on this basis - nothing to worry about. But the TV audience is mostly on land. There are many other weather apps available.
So, how to balance the information?
Local knowledge tells us that waves are often 0.3m to 0.5m higher than forecasts – so the summary for Friday is reasonable winds with some gusts but a sea swell consistently between 2m and 2.5m.
Our boat is commercially coded for conditions up to 60 miles from shore, up to Gale force 8 winds and waves up to 4 metres high. However the conditions for comfortably running tours are significantly less than this and any waves approaching 1.5m - in our area- demand serious consideration of whether the tour should be run. So, regular 2-metre-high waves, forecast consistently over several days, means that the forecast is accurate and that both a departure from Dunbar harbour and a landing for passenger tours at the Isle of May, are not practical.
These specific sea conditions are caused because the preceding two days have had generally northerly winds. Waves build across several hundred miles of North Sea which culminate in a high swell and large waves that reach us on the second or third day.
And that’s why tomorrow, Friday has reasonable winds, but high waves at Dunbar and the Isle of May.
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