I want to buy a boat? help!?

Hello, I live in Ontario, Canada. I want to buy a small boat approx. 15ft with a mercury 1500 2 stroke motor on it. It's a 30 year old boat that is running an doesn't need much work. What i want to know is, do i need insurance? i read several articles that say you don't. I'm not worried about damaging the boat and losing money. My concern is what happens if i have people on it and something happens ? I'm getting my boat license. I just want to know what i need to get this thing in the water and have some fun!!! Thanks