The APA is a percentage of the value of the charter which is set aside for additional costs that would incur during your stay on board. Berthing fees, restaurant deposits, fuel and provisions are example of some of these costs. This is required for every charter regardless of the type of contract or destination.  This amount is usually 30%-40% of the value of the charter which is held in an account and managed by the Captain. The expenditure can be tracked by the charterer directly with the Captain during their trip.