What’s the definition of a powerboat

What makes a motorboat a powerboat? That’s a discussing I had with some fanatics a while ago. Is it determined by the shear length of the hull and the number of engines? Does it matter if they’re inboards or outboards? Does it matter if the boat runs on petrol or diesel? Is any boat with a motor a powerboat? Is it just the horse power or the top speed? So many questions and variables. We also looked at the powerboat racing world. There are the rules that speak of a power to weight ratio like 1 hp to 4.5 kg (petrol, 9.9 lbs) or 4.4 kg (diesel, 9.7 lbs ) like the UIM rulebook states for the SuperSport category. I’m curious about your thoughts in this matter.