Shipping (Ships) is one of the sub-categories of the Build Menu, found in the Goods category. Shipping is used to help get supplies (goods) for Businesses in CityVille. It is unlocked by completing goals or having a certain amount of neighbors. Another way of gaining goods is by Farming.
Upgrading your piers will allow more storage and extend the dock to accommodate more ships. Completion of pier levels or certain goals will unlock/reward new freighters.
According to Zynga's Board all ships may now be stored in the Warehouse.
Depending on the type of ship/freighter used for the shipping contracts, the cost will be higher and the amount of goods will also increase. The ship's return time and requirements will remain the same. The benefit is getting more goods for less energy used to unload the ship.
Depending on the type of shipping contract, the cost will be higher and the amount of goods will also increase. The ship's return time will remain the same. The benefit is getting more goods for less energy used to unload the ship. These boats offer multiple boats in one, to assist limited space issues. They only exist on a Super Pier.