Wave Polar

A wave polar is a vessel performance model that describes how waves affect boat speed and handling from different directions, heights and periods. Like a sailing polar for wind, it translates sea conditions into expected speed loss, motion or efficiency changes for a particular hull and loading condition.

For passage planning, wave polars help skippers choose routes that avoid slow, uncomfortable or damaging angles to the sea, especially when beating into swell or running in steep following waves. They complement Polars, Sea State and Weather Routing by making forecast waves part of the performance calculation, not just a safety note.

In PredictWind, wave forecasts can be considered alongside routing results, GRIB data and vessel performance inputs to assess realistic arrival times and onboard comfort. Related wave fields include Wave Height, period and direction, which together determine whether conditions are favourable or likely to reduce speed.