Voyages can either be deleted from the Voyages or the Fleet Plans module.
Open the module, either:
Go to PlanningFleet Plan.
At the top, select "MASTER" fleet plan.
Go to CoreVoyages.
Click to open the voyage you want to delete.
At the upper right corner of the panel, click Delete.
Click Confirm to delete the voyage.
Only voyages in the "MASTER" fleet plan of status "Estimate" and "Unallocated" can be deleted.
If the voyage has a different status you must change the status before you can delete.