We run thirty one scheduled trips a week across four circuits, and each one leaves at a published hour and calls at its islands in a published order.
That order matters more than the timetable. If you are third on a circuit you know your delivery lands about ninety minutes after the boat leaves, every time, and you can have somebody at the quay rather than sending a boy to look every half hour.
We leave on the hour whether or not every customer is ready, which upsets somebody most weeks. A run that waits for the last load is a run nobody else can plan around, and the customers who are ready pay for the one who is not.
Space on a circuit is booked by the season or by the week. A guesthouse or a shop with a standing booking has its volume held even on a busy day; casual cargo goes on when there is room, and we will tell you honestly when there is not.