No, the young teenaged female employees on the boat were NOT willing participants. If I was one of them, I would be traumatized. Maybe I'm just not used to seeing people perform sex acts in public.
If there were people there who were not willing participants, then I stand corrected.
A majority of those young women employees have done the acts they were witnessing, only in private. Undoubtedly they were offended but I doubt the young women were 'traumatized'.
Now if they'd been 8 or 9 years old instead of 18 or 19 that would be an entirely different thing.