A father has described how his 14-year-old son died in his arms after he became entangled in a propeller having been thrown from their speedboat during a day trip. Charlie Hutton and two friends were on board the rigid inflatable boat driven by his father Simon when they were hit by a large wave close to the Needles rocks off the Isle of Wight.

Charlie, a keen hockey player from South Croydon, fell into the water along with a friend. His father, a graphic designer and keen boatman, said the boat was hit by two waves at the side causing him to slow down before it was hit by a large wave at the front.

He said: "It was choppy but nothing the boat couldn't handle. The two [waves] came from the side and then the water almost dropped away. It was like there was a big drop and then the wave came over us, it was like a big wall of water. I have never come across a wave like it, it engulfed the boat."

Hutton said he believed Charlie was washed off the back of the boat. He said: "I still can't work out how Charlie got where he got." The friend who had been washed overboard suffered an ankle injury but was able to get back on board.

However, Hutton told the inquest at Newport on the Isle of Wight that he remembered looking back and screaming: "Where's Charlie?" He said his mind was "buzzing" as he realised that what he thought had been a metre square patch of oil was blood.

The boy had become tangled in the propeller. He said: "Charlie was conscious and looking at me, I tried to pull Charlie on to the boat but couldn't. I saw his head bobbing, he was saying: 'Dad, help me.'"

Hutton said that he managed to cut Charlie's clothing from the propeller and pulled him on to the boat where he performed mouth-to-mouth resuscitation. He could see that the boy had suffered two wounds to the top of his legs.

The father said: "His eyes were open and he was looking at me. I tried to protect his face and told him I loved him, we all loved him. I could see Charlie's eyes begin to roll, his breathing became shallow. I think he died at this point." Hutton said he phoned his wife, Gill, and told her: "I think I have killed Charlie."

The inquest heard that Charlie was airlifted to Southampton General hospital where he was pronounced dead. A postmortem examination showed he died of multiple injuries to his pelvis and left leg.

Hutton said that he did not feel he had been driving the £50,000 boat at excessive speed when the accident happened on 20 July last year. But he said that if the propeller had been fitted with a guard his son would probably have survived. He said: "If I had been aware of them I would probably have had one fitted."

Caroline Sumeray, the Isle of Wight coroner, recorded a verdict of accidental death and called on the leisure boating industry to promote the use of propeller guards to prevent further similar accidents. She said: "He was a very talented and lovely looking boy and I hope there will be lessons learnt from Charlie's death."