Also, the vantage point is about 30 feet up from water level. You can get a better sense of the swell size at the beginning of the video when the boat is further out and its cabin almost disappears between the swells.

The charter company we used does crewed day sails. They said they had a passenger mutiny the day before in similar conditions, and had to turn around midway to St. Barts. (Unfortunately for the passengers, that meant a windward slog for the return trip). Because of that they cancelled all trips the day this video was taken. We were OK out there and didn't feel at any time like we were at the limits of what the boat could handle, but it was a rocky lee shore that deserves respect and the conditions were spirited enough that we weren't happy going to windward or anywhere near a lee shore. If anything broke it could have had very bad consequences, and being a charter boat we didn't have a lot of confidence in it.