Open World Ship Builder?

So I had this idea to make a really cool 3D game. I would plan to make a procedurally generated world that never ends, a full survival system that uses hunger, thirst, health, and maybe even temperature. Also different types of armor/clothes. But that’s not everything. I would plan on making a full, physics based, vehicle creator system where you can build anything from submarines to planes, Boats, ground vehicles, anything! And it’s all based on your level of creativity. At first, when you only have access to basic materials, you build wooden sailboats with cannons, but when you have better tools, you can make large, modern warships with guns that shoot for miles. I want to know what you guys think of this idea, and also some suggestions to improve it.

Well, it’s gonna take a few years, but it sounds good.