About Seamile

Seamile is a small collection of numbers we kept looking up on the water: speed conversions, the Beaufort scale and a few rules of thumb. Everything runs in your browser; there is nothing to install and no account to create.

Why knots?

Knots tie speed to the nautical mile, which in turn ties distance to latitude on a chart. Once you get used to it, estimating passage times becomes much easier than juggling kilometres.

Accuracy

Conversions use the international definitions (1 knot = 1.852 km/h exactly). Beaufort descriptions are the traditional open-sea ones; conditions in harbours and on lakes look calmer for the same wind.