A man was struck in the face by a model speedboat which flew out of the water and hit him as he sat on a park bench, leaving him with a fractured cheekbone.
The boat's owner lost control of the machine
Peter Nugent, 34, who also needed seven stitches for a cut forehead, said: "I could've been blinded or killed."
It is thought interference from another radio-controlled machine caused the boat's owner to lose control of it.
Mr Nugent, was with a friend and his friend's two daughters in Birkenhead, Merseyside, when the accident happened.
The father-of-one said: "I was just having a relaxing afternoon by the lake with my friend and his two girls, watching the birds and the boats.
"We were sat on a bench and he said, 'That boat's coming towards us pretty fast'.
"I said, 'No, don't be silly'. Then I saw it fly out of the water and it was heading straight for him.
"I pulled him out of the way and it hit me on the side of the face.
"I'm still in a lot of pain but I'm counting myself lucky that it didn't catch me full on."
Mr Nugent's friend, Tony Wallace, said Sunday's incident was a freak accident.
He said: "There was only a couple of boats on the lake and we were the only group of people in that area, and the lake was full to the brim with water.
"It was one of those one-in-a-million accidents.
"People around here have all been laughing about it, because the idea of being hit by a model boat sounds funny.
"But then you tell them about Peter's injuries, or that it could have been one of the kids, and they realise it could have been a tragedy."