LEEBOW · OFFSHORE PREPARATION

What if the boat is slower than planned?

Compare two routes calculated with the same weather and course, at 95% and 85% of polar speed.

GateStartNorth markFinish95% polar speed85% polar speed
Saved routes from the synthetic example. Departing at 13:15 UTC; north is up.
Polar speedElapsedDistanceArrival (UTC)
95%114 min13.53 nm15:09
85%126 min13.56 nm15:21

At 85% of polar speed, the boat arrives twelve minutes later. The routes cover almost the same distance, so the difference comes mainly from the assumed speed.

Use a performance estimate that reflects the boat and crew when planning an arrival window. Review the plan if the observed wind, waves or sustained boat speed differ from its assumptions.

Model inputs and limits

Both runs use the same wind (11.8 kt), significant wave height (0.8 m), current, depth checks and course requirements. Only the fraction of polar speed changes. Departure: 13:15 UTC. Forecast cutoff: 12:00 UTC, 13 September 2026 (synthetic forecast).

The native routing solver calculated both routes from synthetic weather and boat inputs. They are illustrative and unsuitable for navigation. In both runs, wind exceeds the stored polar range, so the solver clamps the top curve. The comparison does not establish boat performance at that wind strength.

Offshore preparation with Leebow