I thought I just responded, but my answer seems to have disappeared. I looked again to see my countdown clock and couldn't find it. So here goes again.
On the Carnival Inspiration shortly before 9/11, I couldn't tell that anyone cared who was there and who wasn't. I was not aware of anyone even checking. I never heard the drill mentioned again either. I got the impression that their attitude was "O.K., we've got to go through this, but if the passengers don't care, we don't care either."