Object that contains all the vessels and voyages (the estimated and unallocated voyages are not part of any FleetPlan of a given fleet).
The FleetPlan with code MASTER is the operational fleet.
The voyages are connected to a FleetPlan through FleetPlanVoyage.
FleetPlanVoyage has a link to a voyage and a vessel and a sequence of the given voyage in the feet, for the specified vessel, the newest voyage will have the highest sequence, for the given vessel.