Bethany Farrell (pictured) was on her first scuba dive when she drowned after becoming separated from her instructor at the Great Barrier Reef . A British graduate drowned on her first ever scuba dive – just days into a dream trip to Australia. Bethany Farrell, 23, died after she became separated from her instructor while swimming on the Great Barrier Reef, a week after beginning her gap year. She was found 35ft down on the seabed in Blue Pearl Bay, a beauty spot popular with divers. Her devastated parents have demanded to know why she wasn’t properly supervised. An investigation by the Office of Fair and Safe Work and Australian police has begun and may lead to criminal proceedings. Statements have been taken and equipment seized. Miss Farrell’s father Patrick, 47, said: ‘She was on a supervised activity – she should have been safe. It has just been devastating. From what we can gather, Bethany had boarded a bus to get the boat at 1pm. She was dead by 5pm. ‘We have photos of her looking like she was having fun. There are times when I have just been hoping I had gone insane and got it wrong. Bethany was a pure and gentle soul.’ The former soldier, who lives in Colchester, Essex, last spoke to his daughter on Skype two days before her death. Mr Farrell, who is divorced from Miss Farrell’s mother Caron, said: ‘The instructor had three students, one of them was Bethany. One of the students decided she did not want to dive but we have not got the exact reasons why, so she remained on the boat which left the instructor, Bethany and one of her friends. ‘At some point, the diving instructor lost sight of Bethany, then realised he could not locate her, returned the other student to the surface, sought help and went back down, presumably with some other people to help. ‘They found Bethany dead 11 metres down. They were meant to be diving to a depth of 5 metres.’ The family has been told it could be months before the events leading up to Miss Farrell’s death are fully understood. Miss Farrell, who studied English literature and media at Southampton Solent University, had been in Australia for a week and met up with some friends who were already there. She had been planning to work in the country for a year and posted a series of images to her account on photosharing website Instagram in the days before her death on February 17. Police and safety inspectors are still investigating her death on February 17 at Blue Harbour Bay (pictured) Her father said his daughter was a competent swimmer who had signed up for introductory diving after snorkelling lessons, before she then progressed to scuba diving. He said: ‘A lot of her friends said they had never seen her so happy.’ Graduate Ms Farrell (pictured)  was found drowned following her first ever scuba diving trip at the Great Barrier Reef in Australia in February . Her mother, 50, said: ‘For the first few days it was like a bad dream. We have got pictures of them all with the snorkelling equipment. They are all smiling.’ Miss Farrell worked during her university course as a shop assistant in a stationery store and a bartender. After graduating she was employed at Laura Ashley in Colchester and, in the days and weeks leading up to her trip to Australia, she excitedly tweeted about the adventure. On January 14 she wrote: ‘This year is already off to an exciting start – one month to go!’ Three weeks later, shortly before leaving, she joked: ‘Packing light really isn’t in my vocabulary.’ She took a number of photos through the plane’s window on the flight to Australia and wrote to one of her friends on Instagram: ‘I am very excited – it’s been a long journey…I just want to get there now.’ Miss Farrell, who was staying in a youth hostel, had a younger brother, Jake, 20. The Professional Association of Diving Instructors said the instructor would have been allowed to take four students to a maximum depth of 12 metres. But a spokesman added that discretion should be exercised, saying: ‘This is in ideal conditions with really good students.’ Blue Pearl Bay is on the north-western side of Hayman Island, part of the Cumberland Islands off the coast of Central Queensland. Underwater visibility of 50 metres means that it is a popular destination for snorkelling and scuba diving. An investigation was launched immediately after Ms Farrell (pictured) was found dead - it could take a year .
Bethany Farrell died on her first ever scuba dive at the Great Barrier Reef . British graduate, 23, became separated from  instructor on diving trip . Group were diving in 5 metres of water - she was found dead at 11 metres . Devastated parents say they are still trying to understand what happened . Australian Police and safety inspectors are still investigating her death . They have told her family the investigation could take more than a year .