You can make models. You just need to find a software you can use/afford/free, and stick with it. The program I use costs $1000 dollars, but if you are or have one in your family, you can get it through them(the student) for $200 dollars, and as an adult must buy it, all you need is a valid school I.D.. I use Rhino 5.0 64, it is a Nurbs modeling program, as it's specialty, but also does Non NURBS CAD. I have used it for years, and have designed real car parts, my Barn, reverse engineered airplane parts, designed models, and made parts for real boats, and real motorcycles. You own this software when your purchase it. You are allowed to put it on 3 computers at a time!! I could spare you years of aggravation, and some of the best designers on this forum use it. It just takes a cash outlay, and a lot of sticking to it. There are manual ways too. Many work really well for lofting ship hulls, one of the harder things to do. One has to study up on the subject matter to know what is necessary to reproduce, and what isn't. If you can build models as well as you do, see what you are making, and start to reproduce it in different forms. A ship hull can be a battleship, widened and shortened a bit, a sailboat. It is a matter of perception.