Boating in the Caribbean: the best day to go

The trades are the point. They blow from the east for most of the year with a reliability that makes the outbound leg easy and the way home the one to think about, and the Atlantic swell that arrives with them keeps running through the channels between the islands even on a quiet day. Between the islands you are in open water. In their lee you are not.

Bonasea resolves the sea against your course on every leg, so the run down and the slog back are scored separately rather than averaged into one number for the day: in the effective wave, a following sea counts least, head seas more, beam seas most. Tide height at your arrival and the depth in the anchorage corrected for it come with it. Hurricane season is not something a comfort score speaks to — for that, the official warning service for these waters is the only thing worth reading.

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.