When you charter a motor yacht or a yacht which is booked under MYBA terms, it is required that a deposit is paid in advance of the charter. This amount is separate from the actual charter rate of the yacht or booking.  This deposit is what is called an APA; Advance Provisioning Allowance. The title of this terms clarifies the meaning behind the deposit.

What is Advance Provisioning Allowance (APA)?
The APA amount – ranging from 25% to 30%, and in some instances higher, is used to cover the expenses incurred during the charter period. This includes services and items such as fuel, food, beverages, mooring fees, private marina fees, visa fees if applicable, harbor fees, park fees, taxes, and other expenses not included in the charter rate.
The Captain of the yacht is responsible for keeping track of these expenses during your trip. He/she maintains the accounting for all APA expenses during the charter. At the end of your private yacht charter, the Captain provides a breakdown and presents it to you for payment.
In the even the costs incurred during the time of the charter, are less than the paid APA, then the difference will be refunded to you, the charterer, at the end of the charter.
The same applies if the costs incurred during the time of the yacht charter, exceed the paid APA, then the difference is payable by the charterer at the end of the charter period.
Fuel costs vary per country; as well the yacht consumption varies for each yacht chartered.