By Phil Mercer in Sydney

The death of British tourist Nicki Sheen off Bondi beach is the second diving death off the coast of Sydney in two months.

In December a Japanese holiday-maker drowned at Manly. Once again the safety of Australia's scuba industry is under scrutiny.

Police in Sydney are examining the equipment used by the 24-year-old Londoner and could bring charges against the dive company.

Nicki drowned on Saturday after running out of air. She had arrived in Australia after completing a diving course in Thailand - these courses are popular with thousands of backpackers from the UK.

Geoff Schrimski, an instructor at Sydney Scuba, says some sub-aqua centres in Asia just are not good enough.

Panic

"People are under the impression they pay their money to do the course and they will automatically get certified at the end," he said. In the majority of cases they do, when in actual fact maybe some of them shouldn't."

Mr Schrimski believes there are also problems Down Under. "Some people here have a sausage factory mentality. They just want the money and churn people out as quickly as possible."

There is also a worry that many inexperienced divers are ill-prepared for the cooler, rougher seas off Sydney compared to the tranquil, tropical waters where they were trained.

Isabel Fuezee, a 29-year-old from Montreal, says her first dive here was a nightmare; "I couldn't see through the mask. It slipped off and I just had water everywhere.

"I didn't know what to do. There was a two-second period of absolute panic - I couldn't see, I couldn't breathe" She was saved by the prompt actions of her scuba partner.

It is midnight and the 30ft boat Southern Comfort is taking a group of divers to explore the wreck of The Currajong, a tanker which sank after a collision in Sydney harbour in 1910.

All are vastly experienced but follow the safety rules to the letter. "Whilst you're diving should you hear three revs of the engine in quick succession, that is our diver recall," said Julia, the dive master.

"Please surface slowly and look to the boat for instructions."

Sufficient supplies

No-one dives alone. Equipment is checked and then checked again.

Geoff Schrimski says it is vital: "The main thing is to monitor your air to make sure you've got sufficient supplies all the time.

"The rule is you check it every five minutes." A roster tells the crew how many divers are underwater at any one time. Each name is ticked off on return.

"My view is that the dive industry in Australia is very safe," says Bill, the skipper.

His advice to tourists is that they should shop around.

"They should go not to just one operator - but visit a few. Talk to them and get an impression of how professional they are. And remember - the cheapest isn't always the best value when it comes to safety."