Yeah there is definitely a lot of gray area with this one. Agree that it's really how the law is enforced.
I was on a center console fishing boat years ago going through a no wake, the only 2 seats were behind the wheel. While going though the channel, we got stopped & MP said I was sitting on the gunwale which was about waist high. I defined it more as leaning against. I would say the way I was sitting (or not
) was safer than the picture above so better not give them a reason to stop you.