Hello, this is a detailed tutorial on how to make [modern] ships in Minecraft, I will be using an example ship, the famous patrol torpedo boat [or just pt bat] pt-109, captained by John F. Kennedy. This is a tutorial for any kind of ship, meaning that the tutorial isn't on the PT boat.

Step 1: 2D Stage

For this stage, you just make a 2D version of your ship, this will house the backbone of the ship, the keel.

Step 2: Framework Stage

So, for this stage, just make a skeleton of your ship, this will be the main sort of structure, and the support for the outer hull. your "ribs" shouldn't be too far away, because you will need to connect them later.

Step 3: Hull + Deck

So, for this stage you close off your "ribs", and you fill in the under hull part, and you also need to put a rudder, because it steers the ship, and also a propeller.

Step 4: Superstructure + Guns

So, for this stage you make your deckhouse, and the bridge. the bridge is where the captain is at, and where he steers the ship. I also put some machine guns on deck, and the "mosquito's sting", the torpedo. I put four powerful torpedo tubes on the sides of the ship.
Now, the interior is up to you!
I hope you enjoyed this tutorial!
Please comment, give me some feedback, constructive criticism, and some suggestions!