Different directions we can take the model.

The key side is quite old so it is impossible to have people aboard the submarine while it lowers (as it would make the key side crumble) so the architect of the project has come up with a solution. The audience outside will see a steam punk style fishy submarine which will be seen to be lowered into the harbour with people who have seemingly just gone aboard. The audience who come aboard will go past this large model of a submarine in tunnels which will lead them to a second submarine which is already submerged in the water. On this submarine they will watch a puppet show outside of the portholes. So the model needs to include the walk ways, the 2 submarines, the key side and the box office. The more elaborated submarine model could move if possible, or could be made a second time as a separate model in more detail.