Boating on the US West Coast: the best day to go

The Pacific sends a long swell almost every day of the year, and a long swell is a different problem from wind chop: you ride over it, right up until it meets an ebb at the Golden Gate or shortens over a bar. Inside Puget Sound the water is sheltered but the current is not negligible, and the summer fog off Northern California turns up on the same afternoons as the northwesterly.

The effective wave is where this shows. A long, slow swell is discounted, because the boat rides over it; a short-period sea is penalised, because closely spaced crests hit harder. That one difference is most of a Californian afternoon, and it is why a day with a big swell running can score better than a day with a smaller but much shorter sea. Tide height at your arrival and the depth in the anchorage corrected for it come with it.

Depth figures are modelled averages rather than a survey of your bay, and the comfort score is an estimate from weather models rather than a promise. Bonasea does not replace official charts, publications, regulations or the skipper’s judgement. Read the warnings for these waters before you leave, and trust your echo sounder over the app.