'I'll be thinking about her every stroke I swim'

Dr Chrissie Thirlwell is swimming the Bosphorus, a sea strait from Asia to Europe

A woman is preparing to swim the Bosphorus, a sea strait from Asia to Europe, in memory of her life-long friend who died earlier this month.

Chrissie Thirlwell, 53, a doctor and university professor who lives near Bristol, has taken on a number of cross-continent swims after swimming the English Channel in 2007.

Dr Thirlwell paid tribute to her friend Kirsty Widdowson, 53, who died from Marfan syndrome, a genetic disorder affecting connective tissue: "I'll be thinking about her every stroke as I go through the swim," she said.

The event, which is run by the Turkish Olympic Committee, is 6.5 km (4.04 miles) and includes 2,400 swimmers from 50 countries.

Dr Thirlwell swam the English Channel in 2007

"When I was thinking about doing this in Kirsty's memory, I spoke to her partner, Steve, and to her sister, Lindsay."

"They both immediately said, 'oh, that would be fantastic. She would have loved it'."

"She would have told me I was crazy, but they knew that would make me want to do it even more, she added.

"She was just the most amazing woman," Dr Thirlwell said.

Dr Thirlwell is swimming in memory of her childhood friend Kirsty Widdowson who died earlier this month.

"It's a really international and quite exciting race, where you get in on the Asian side and land in Europe," Dr Thirlwell said.

Two previous attempts at the swim were halted by sickness and strong winds forced the organisers to cancel the event.

"I'm really just looking forward to finishing this group of challenges and really reeling it in, in Kirsty's memory," she added.