Phenomenal atmosphere you've achieved here, the water looks great, the soundscape is amazing, and everything looks/sounds just right for what you were trying to accomplish.
I liked the idea of more-realistic sailboat controls in theory, but I agree with others saying they had a lot of issues with them in practice. The main thing that I found frustrating was that there was something weird with the character being positioned to one side or the other of the sail and the camera would often getting stuck behind the, mainsheet, I guess it is? Whatever the line is called that controls the angle of the sail. It often felt like I was fighting the camera moreso than the sailboat or the wind. When that happened I couldn't see the radio or much of anything unfortunately.
In any case the story hook and atmosphere grabbed me so much that I persisted and eventually got a little bit of a hang of it and was able to get to the ending, but it always did feel a bit janky trying to get the ship moving and pointed in the right direction.
Basically loved everything but the controls/camera issues and I thought it was a memorable and poignant and scary game despite my struggles. So great work on all of those things!