My worst trip ever was from Phuket to Phi Phi in ´93 in a big speedboat ferry with a bunch of Koreans.
The sea was quite rough and the boat was hitting the waves and them Koreans, they must have had lunch just before departure, them smart cookies, started to vomit all over the place. Them retching noises, the smell, the sight, I don´t get seasick easily, but thanks to their attack on my senses I felt a bit queasy myself, but still did not get seasick, just disgusted.