Funnily enough, I don't get seasick in heavy seas - even below deck without a horizon - but I will sitting at the dock with light motion. It's like my vestibula

Funnily enough, I don't get seasick in heavy seas - even below deck without a horizon - but I will sitting at the dock with light motion. It's like my vestibular system "knows" to shut up when the chaotic motion goes beyond certain parameters.