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

Tides of one to three metres change what the day looks like, and in the narrows they arrive as current: the Race, Plum Gut, Hell Gate and the mouth of the Chesapeake all run hard enough that the state of the tide decides the hour you leave. Add the short, sharp chop the Chesapeake builds in a summer southerly, the swell that works its way round Montauk into the eastern Sound, and the fog that closes in on a clear New England morning.

Bonasea gives you tide height at your arrival time and the depth in the anchorage corrected for it, and scores each leg on the sea you will actually meet — a beam chop across the Sound counts most against your course, the same sea behind you least. The HRRR model resolves the coast finely enough to see the sea breeze. Two honest limits: tidal currents are on the roadmap rather than in the score today, and visibility is not modelled at all, so fog stays a matter for the forecast and your own eyes.

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.