Large-scale warship models already exist

Have modelers built very large battleship or cruiser models at scales such as 1:25 or 1:100?

Yes. Examples include the large Yamato museum model, working models displayed on ponds and artificial lakes, and a roughly 2.5-metre model of HMS Hermes.

Modelers and museums have built warships at impressive scales. Examples include the Yamato model displayed in its namesake museum, large models operated on ponds or artificial lakes for demonstrations, and a roughly 2.5-metre HMS Hermes. These objects bridge technical modeling, public history, and the physical impression of ship size.