Conditions: 12 - 19 knots of wind, 0.3m wave height, and next to no current (just a tiny bit of current flowing out of the fjord). The wind was slightly gusty/disturbed due to surrounding trees and hills.
The Boat & Mindset: Nonsuch 36 in cruising mode—definitely on the heavy side with an 11ft RIB and a 15hp outboard on the davits. My mindset was all about keeping the wife and cat happy, while still trying not to fall behind the other boats heading the same way.
I shared the GPX file with an AI tool, which claimed my best tack was about 80 degrees (tack-to-tack). My actual average COG tack-to-tack was 88 degrees (meaning about 44 degrees to the wind).
Please ignore the wind instrument data on the dashboard display; the screenshot was taken while we were safely moored, not while sailing.
Given these numbers, I’m wondering if I was pinching too much. Would the Nonsuch have performed better (higher VMG) if I had cracked off a bit and sailed a slightly lower, but faster angle?
A 44-degree angle to the wind (88 degrees tack-to-tack COG) felt pretty tight for a loaded Nonsuch 36, but I’m curious to hear your thoughts and experiences on the optimal upwind angles for this boat.
You’ve captured useful data, but not enough to form an opinion about how close you are to optimal upwind angles. I’ve collected similar data on Soave (NS33) which suggests the angles you’re testing with are reasonable but I haven’t proven they are optimal. In my case, the current on mid LIS is too variable for precise analysis. My intuition is similar to yours, in the lower range of the 12-19 wind I’d try easing the angle to improve VMG. On Soave at the high end of your range I started to experience weather helm, so I branched off to focus on boat and sail trim so I wouldn’t be using as much rudder.
Looks like the sample rate of your GPS is faster than mine, your course plots look smoother.
Maybe you could get your AI agent to report average tacking angles rather than best. You’d probably have to trim the file so it only includes close hauled sailing.
I’m no racer but I do have all the instruments it take to show VMG wind on my display. With this data available it’s easy to point up or bear off and watch the number to see what is optimal.
I don’t do a lot of tinkering with my sail because I’m basically lazy but I find that for my boat (30U) with me sailing it, the optimum upwind angle is ~28° apparent in most conditions.
