The Voyages tab can be found in the Fleet Plans module. It contains a list of all voyages that can be found within a scenario. This includes voyages of status unallcoated, allocated, estimated, nominated, etc.
The following voyage information can viewed from the list:
Clicking on a voyage opens the voyage drawer and gives access to additional information and actions.
You can read more about the actions here: Voyage Actions.
There are several sorting and filtering options available for you to narrow down what you include in the list view.