She was dragged into deeper water by her attacker who gave his name as Dabby, police revealed yesterday.
The victim said she was with friends just west of Bournemouth Pier on July 18 – one of the hottest days of the year. In a statement released by Dorset Police, she added: “It was around 4pm when we went into the water where my friends and I had a ball.
“It landed next to a man – or a boy. I asked, ‘Can you give me the ball back?’ and he said ‘No’. I came closer to him and asked again – he gave it to me and I threw it to my friend.
“He started talking to me and touching my arm. At the same time, another man was making my friend uncomfortable so she left the sea. I was alone now and he started to push me out into deep water. No one could see what was happening and it was then that he raped me.”
The girl added that a friend of the rapist, who may be of Asian origin, then approached so she managed to reach the shore.
In a statement read out on BBC1’s Crimewatch Live, she went on: “I was in tears. I told my friend what had happened and I was really hurting.”
Her attacker followed, asking how to contact her, before her friend made him go away.
She added: “Since it happened I’ve changed a lot – I can’t face going out and I feel frightened and vulnerable. I am so scared that people will judge me for what has happened.
“I didn’t ask for this – I tried to stop him but I couldn’t.”
Police yesterday renewed an appeal for witnesses.
The rapist is described as possibly of Pakistani descent, around 5ft 7in tall, of thin but muscular build with short dark hair that was pushed back. He was said to be wearing black or grey swim shorts.
Det Inspector Wayne Seymour said the attacker had a ring in his left ear and his left eyebrow was slit.
He added: “He told the victim his name was Dabby, he was 17 years old and from Birmingham.
“I would repeat our previous plea for anyone who exchanged Snapchat messages with a number of young Asian men who were reported to be approaching female beachgoers on the date.”
Officers hope that one of them will recognise the e-fit of the suspect.