How do boat dealerships work?

I'm in the market for a boat, and I'm just curious how boat dealerships manage their inventory. Do they purchase the boats themselves, finance the boats from the dealer, etc.? How much of a markup is there on boats? I'm just wondering how much wiggle room dealers have with the price. It seems to me that they must mark up the boats quite a bit, otherwise, how do they stay in business with such limited inventory moving month to month. It's not like a car dealership that moves a lot more.

Just looking for any insight into the process. I want to know if they give me "their best price" if there really is any more room to negotiate.