Booking a spot at a marina for a yacht charter?

When you are chartering a yacht for a week in the Caribbean or Med, are you required to book a marina slip for the first and last nights?

It's a random question that came up as I was looking at yacht charters. Under the MYBA contract the charterer is required to pay all marina costs, but the contract also states that it starts and ends at a specific marina... do you actually need to stay at that marina? What if you have no intention of staying overnight at a marina, you want to immediately motor somewhere else for the night? If the charterer doesn't want a spot at a marina, does that complicate turning over the yacht at the end of the charter like getting the garbage off the boat and getting the next charter's supplies onto the boat? What happens if there are no slips left at the marina by the time the charter is booked, is it a big deal?

Looking at marinas it seems that most charge per night like a hotel, without hourly or other shorter term options. So it seems like if you wanted the yacht to be in a slip when you took delivery at 5pm, but wanted to immediately head out from the marina, then you would still have to pay for the whole night, which is why I wondered whether you could just skip the marina slip.

Or am I thinking about this all wrong, are slips always available and at infinitesimal prices relative to the overall cost of the yacht charter, so that even if the charterer only wanted to stay in the slip for a couple hours he wouldn't think twice about paying for the whole night.

Thanks that makes sense. The nightly dockage at Caribbean marinas does seem very small compared to the base charter costs.