Estimating the SunCat Leeway

[Joseph]

The SunCat is reputed to have a significant leeway. A few weeks ago, on a short daysail, I set to do a series of tacks up-wind in Lac Deschênes, a broad portion of the Ottawa River. The wind was N–NW at 8-12 kts. Waves were heading downwind and were of abt. 1-2 feet. The boat averaged a SOG (speed over ground) of abt. 2.5 kts. The sail was trimmed with the end of the boom just outside the railing and the sailing angle of the bow to the true wind was abt. 50º. The current in this portion of the river is set S-SE and accounted for 5º downwind. Hence, since the GPS tracks showed tacking angles of 144º, the SunCat leeway in the above conditiions was estimated at ((144/2) - 50 - 5) = 17º (+/- 4º). I’d be curious to know how this estimate compares with those made by others.

J.