Going on a sailboat holiday is a social experience. Some people go to meet new friends, some others prefer to go with their friends or families. To meet everybody's taste, we give them opportunity to book a single spot or the whole boat.
In the second case, users expect, of course, to pay less for the whole boat rather than booking singularly all the spots available on board. We recommend you to adjust the price in order to valorize the whole boat booking. At least 15% discount would be appreciated.