I am going to Florida in a few weeks and thought about trying out surfing. Have you ever surfed?
I have never surfed, and I am not sure I would be any good at it. It does not help that I am afraid of the ocean.
Yes, that doesn't help. I don't think I'd be very good at it either. But, it does seem fun!
There are also waves in lakes and oceans, but I think I would still be too afraid.
Yes, it would be interesting to actually see someone surfing in a lake around here, but I haven't yet.
I have seen people surfing in Lake Michigan before, but that lake is huge!
Yes, I imagine Lake Michigan is! I've seen people being pulled by a boat, water skiing, etc. But, never surfing in our lakes. 
Water skiing requires a lot of space so I imagine you can surf if you can water ski.