I like boats. I make my own RC Depron cut airboat almost every year. It's a nice weekend project: simple to build, simple to operate. Even children can have fun with airboats. They are safe enough and simple to run.
This year's airboat is a slightly more advanced model than most RC airboats out there: it has two motors with a differential thrust, FPV camera, and transmitter, flight controller, GPS and runs INAV. Yeap… it can not do RTH yet, but at least shows distance and direction to home. And this is always something!