I am a lake sailer. And without landmarks or anything it is impossible for me to perceive the boat as moving.
Eventually it made sense that boat-speed only changes the "apparent wind", as it's only simulating wind-boat interactions, not water-boat interactions.
Even some kind of wake or something would help.
I thought I was doing something wrong. It doesn't seem like anything I do has any effect, but guess that's just because there is no apparent effect.