What do we call a factory that builds ships?

A factory that builds ships is referred to as a shipyard. Shipyards are specialized facilities where the construction, repair, and maintenance of ships take place. They are equipped with the necessary tools, equipment, and space to accommodate large vessels, making them distinct from general manufacturing plants or other types of locations where smaller boats or different products might be built.

The term "docks" generally describes the area where ships are loaded, unloaded, and stored, rather than the facility that constructs them. "Manufacturing plant" is a broader term that encompasses many types of industrial production facilities but isn’t specific to shipbuilding. A "boat yard" often refers to a smaller facility that constructs or repairs smaller boats, like yachts or fishing vessels, but not large ships. Therefore, the precise term for a facility dedicated to ship construction is indeed a shipyard.