Shore diving is not always an option which leaves the book! Last time I did a liveaboard we gave 15% as per the "etiquette" which was 600.00$ for 2 people. I think it is a little excessive to request 15% in that case. My point is just that people with less money should not feel bad after leaving 150.00$ per head. Diving is such a great activity, it should be available to as much people as possible.
big dog13:xepi33 first of all stay on the beach refers to beach diving reading a book is optional as for a week of diving say 2 people total of 16 dives $200.00 to 250.00 would be fine I think however when planning a week vacation to throw in an extra 250.00 or so is easy to do