My key point is that if you did a survey of NH across all craft and sailors you will get very different answers. I am very sure of this. NH is a Petri dish of less and more experienced participants across many disciplines. It's also a mix of Wavesailing type sailors with non. So very complex. Also lots of wind compared to other spots and that day was over 30 knots for a while.
If you assume give way to starboard rules every time in that environment the chances are there will be a collision. There is added complexity in that when getting close on windsurfer at speed no 1 is derisk, e.g. slow down. Going downwind does opposite. If danger close dump the gear to take weight out of it. So if I was getting close to someone unexpectedly on a collision course I would rip up wind to take speed out, regardless of right of way rules.
I give way to everyone on the way in when I would otherwise have right of way as I'm not doing any moves when on the way in under port/starboard rules, even though it conflicts with port starboard rules. I will give way when someone is trying to wave ride while I'm on way out too, which conflicts with waveriding rules (give way when on a wave). I have been sailing at NH a very long time and one of the more experienced windsurfers and I don't think ive perceived port starboard rules being used there by pretty much anyone as an assumption.
Therefore if able to be agile enough not to assume it and be safe, you'll be fine. If you assume port starboard rules for all craft all the time, unlikely to end well if your there long enough.
Big global spots have charts to explain this stuff, but not everyone pays attention (Ion club sample below):
Might be a mute point, but aren't you a foil boarder?
