Track Replay

Other programs provide "stripchart" displays to help you monitor wind and other variables. We go further and enable comparative displays, to monitor boat performance vs. targets, observed wind vs. forecast wind, water temperature vs. current, and other combinations. The example below shows measured wind speed and direction (blue lines) vs. wind model predictions (red lines) during a race in San Francisco Bay. By comparing actual to predicted wind, you can determine when and how to modify a forecast, using our point-and-click wind-model editing and development facility.

Strip charts are very useful, but they only show variations over time, not as a function of position. Wind patterns in a confined region, such as a bay, may have a predictable variation derived from the surrounding topography. In a course with repetitive legs, such as a windward-leeward course, wind variations on a given leg can be a helpful clue as to what to expect next time. Our track function not only shows past boat position, but also the wind experienced at that point. You can run this live, or recall and replay a prior race in context, pausing to let the program display the current and wind at that point and time. The example below is a replay of Sayonara's track in the 1998 "Great Pumpkin Race," showing the changes in wind speed and direction in the clockwise track around Alcatraz and Angel Island.