Things You'll Need
Instructions
The Steps
Increase the city's population to 100,000. The marina will not become available to build until the city obtains a minimum population of 100,000.
Choose a location on the coast near your city. The marina must be built partially on the land and partially in the water; it should also be built near your city if there is no space for it inside the city. The marina will not live up to its potential if you place it too far outside the city.
Use the "surface water tool" to dredge out a deep trench next to the land on the spot chosen for the marina. The depth should be as deep as the game allows you to dig.
Place the marina so that the blue boxes are aligned with the water and located where you dug the trench and the other boxes are on flat ground.