alt Hacker NewsSailRhythm is a bit WIP, so didn't want to share too early!
Thank you so much for the detailed feedback. I do have plans to implement wind flow visualization and have a way to visualize forces as well. Controls a bit tricky to do, but this is definitely something I've been pondering. As you said, at certain headings the changes sometimes are too small to perceive.
You're welcome on the feedback, and mostly just suggestions from trying the product / demo. Cool generally that somebody's actually investigating sailing.
Another thought of (if there's actually further interest in this kind of software) would be middleware like SpeedTree (https://en.wikipedia.org/wiki/SpeedTree). Seems like sailing games have been pretty popular lately (Sea of Thieves (40m player base), Assassin Creed IV (15m)) so there's probably at least some market for modestly priced middleware that handles sailing physics.