Been out on the Corsair in 5-6. It was awesome. Probably shouldn't have been out, but hey, nobody had problems. Well, I take that back. Rasta man and I didn't have any problems. Rest of the boat was feeding the fishies on the surface interval.
I personally didn't have any problem. I didn't see anybody on the boat have any problem, except for the seasickness. Now with a boatload of newbies or vacation divers that might not have been the best move, but I think everybody was local on that ride.
Course, I have dove sites when I had to pull myself down the mooring line to get to the site (not easy, I mean superman like flying current). Course we were all club divers, advanced, and there were 2 I believe that didn't feel comfortable and so they didn't go. No harm, no foul. That dive was great. Awesome viz too.