Cristina Ojeda, a 38-year-old doctor from Madrid decided to go for a Christmas Day swim off the Arinaga beach while on holiday with her family.
About 20 meters from the shore, she felt a pain in her arm and saw that a shark measuring about 1.7 meters in length had grabbed hold of it.
"I pulled my arm and it let go," she told Antena 3. "My arm felt like it had been dragged through thorns"
She was left with rows of bite marks across her upper arm, some of which needed stitches.
Hoy he tenido un encuentro cara a cara con un tiburón. Cosas que pasan cuando nadas en Canarias en diciembre. pic.twitter.com/aZ7qSmnEGC— Cris Ojeda-Thies (@ojedathies) December 25, 2015
She posted a photograph of her wounds on twitter but sought to play down the attack insisting that she wasn't afraid of going back in the water.
"No alarmism please," she said. "I would go for another swim tomorrow if it wasn't for the bandage."