"To unload the cargo" means to remove or take out the goods or items that are being transported on a ship, truck, or other means of transportation. Full definition
Dock Workers are found in warehouses and are usually responsible for unloading cargo from ships. (jobhero.com)
Their voyage carried them by Cos and Rhodes and into the Lycian port of Patara, where they changed ships, sailed within sight of Cyprus, and landed at Tyre, where the ship unloaded its cargo. (religion-online.org)