I built a video studio in one of the rooms in my house and have a number of projects I am working on, but as hard as I try, I can't think of a real reason to buy a drone. But I do love the gear.
This will answer your question about drones and water.
If you are into making videos watch his editing it is so cool, and he does it every day. Amazing. Look at this one, from a week or so ago, for example. I think it is something of a minor masterpiece the way with his artful editing he can make things so, well, cool.