Optimizing an electric boat for range is similar to optimizing range for a boat with an internal combustion engine. In short, the more power you draw, the less range you will get.
The below graph shows a theoretical range graph one might expect to see powering with an electric sailboat in smooth conditions.
As you can see, the amp draw to speed is not linear, however, there is a “sweet spot” in which the range is optimized for approximately 22 nautical miles while maintaining an approximate speed of 4.2 knots and at the same time only drawing 23% of the available amp hours. (based on a 200Ah system)
By sacrificing a few knots, there is a 145% increase in range.**
**This graph is for illustrative purposes only and represents a theoretical example. Water conditions and individual boat dynamics will compute different findings.