The latter focusses more on the forecasting and routing of wind and currents for adventurers and competitive sailors participating in ocean sports like yacht races.
They are primarily geared towards protecting owners and charterers from speed claims, a secondary use being to reduce fuel consumption and improve ETAs (estimated time of arrival).
Promoters of weather routing companies cite high fuel savings due to their use, while many mariners tend to be sceptic of their advantages due to a few number of maritime accidents (such as the sinking of the Derbyshire in 1980, and the parametric rolling of APL China in 1998) and cargo damages that continue to occur even when vessels follow routing advice.
A few routing programs employ the Dijkstra algorithm and do not consider the different responses of each ship to the same weather, as the latter is difficult to estimate.
Weather forecasting for long-distance races is based on dissemination of meteorological data, most often in GRIB format, for use in navigation and route planning software and yacht characteristics (polars), providing guidance, as well as analysis of historical weather and sea state data.