A half hull model ship is like a picture of a ship, but in three dimensions. Imagine if you had a picture of a ship, but you cut it in half so you could see the inside of the ship too. That's what a half hull model ship looks like.
Imagine you were playing with LEGOs and you made a really cool ship. But instead of taking it apart when you were done playing, you decided to make a copy of it that you could look at all the time. A half hull model ship is like that copy, but instead of being made of LEGOs, it's made of wood or sometimes even plastic.
When someone wants to make a real ship, they often start by making a half hull model ship. This helps them see what the ship will look like and how it will work in the water. It's like building a little prototype before building the real thing.
People who like ships will sometimes collect half hull model ships because they are pretty and can remind them of their favorite ships. Others might use them to help them design new ships or to study how ships have changed over time.
In summary, a half hull model ship is a three-dimensional model of a ship that shows what the ship looks like inside and out. It can be made of wood or plastic, and is often used as a prototype or for decoration.