There have been lots of lecturers that I thought would be great to sail with. Most recently, Mark Russell was on Seven Seas Voyager whom I would have loved to seen talk and perform. However, I have never booked just because of a lecturer. Being a basically pessimistic person, I feel that if I booked just for the lecturer, I would end up being disappointed when they cancel at the last minute.
Nicole Kidman was on my last cruise. However, I really don't think there is a celebrity that I would go out of the way to cruise with.