You get a feel for the helmsman or his cohort at the stern being tossed around. The camera is shielded from jarring -- if it had been hand held or on a simple "gimbal", it would have oscillating like crazy.
Down below, in the dark, while your sleeping on bean bags, on the crapper, eating or reading -- it must have been like being in sewer pipe with someone hammering on it and running bulldozer over one end of it behind you!
What a video! Shot a night on a sailboat doing 19 knots. Recorded with sound from halfway around the world so you can experience what was happening so closely. Really amazing stuff.