The Shipyard turns the bonuses of the Harbor away from growth and economics and toward naval unit production. It increases the XP bonus for naval units, and if built in a Harbor adjacent to a City Center and sea resources, it will provide a substantial Production bonus. Not only that, but in Gathering Storm, it adds Production even to unimproved Coast tiles, which together with the action of the other Harbor buildings will turn them into really useful contributors to city growth.
If Reyna is established in a city with a Shipyard, the double adjacency bonuses from her Harbormaster title may benefit the Shipyard's Production greatly, depending on the Gold adjacency bonus from the Harbor in the city.
The earliest known dockyards – dating c. 2400 BC - have been found in the ruins of Lothal in the state of Gujarat, India. Naupactus means “shipyard” in Greek; it is not surprising that that ancient city was known for building warships. Every nation with pretentions of being an empire had its shipyards. Ships were one of the first things to be mass-produced; centuries before the wondrous Industrial Revolution, the Arsenal in Venice was able to produce a merchant or war ship in a day, using pre-manufactured and standardized parts on an assembly line. With the advent of iron and steel vessels, shipyards became more like factories than ever, with massive drydocks to build the greatest ocean-going vessels ever … but it took more than a day. At the sprawling Harland & Wolff shipyard in Belfast, the RMS Titanic was laid down in March 1909 but not launched until May 1911, with nearly a year still until completion and its fateful maiden voyage.