ALISTAIR Brownlee is determined to defy Queensland's shark-infested waters and put the bite on his rivals when he defends his Commonwealth Games triathlon crown in Gold Coast tomorrow.

The 29-year-old Bingley Harrier received a stark reminder of the potential dangers lurking in the shallows when he had a close encounter with a shark hook during a sea swim in training last week.

Although the introduction of its Shark Control Programme in 1962 has dramatically reduced the rate of incidents, according to there have been five fatal shark attacks off Queensland this century.

Former Bradford Grammar School pupil Brownlee, who is carrying the England flag at today's opening ceremony, said: "I have spent a lot of time in the sea since I have got out here and we did a big sea swim last Friday.

"I was right out there and I saw the shark hooks, which are set out to catch them if any happen to be around. I swam past and they were about 10 metres away and I just thought, 'woah'."

Brownlee and his rivals, including younger brother Jonny, must traverse 750m of the Southport Broadwater, in which a 2.5-metre bull shark was caught lurking as recently as 2015.

Marine predators notwithstanding, the elder Brownlee's defence of his title is far from a foregone conclusion after a season hampered by his recovery from a major hip operation as well as some time out to focus on longer-distance races.

In fact brother Jonny arrived on the Gold Coast having had by far the better preparations, potentially making him a slight favourite to finally get one over his brother at a major Games.

For Alistair, who once seriously considered targeting either the 10,000m or marathon at the Gold Coast Games, his future path remains far from certain with the Tokyo Olympics now almost two years away.

Brownlee, from Bramhope, added: "I've had a fantastic career and I have to pinch myself about how well it's gone but I'm never sure how good the body or the motivation is going to be.

"I've really enjoyed my step up to long-distance racing and I am going to pursue that at some point but I'm not 100 per cent sure if that is going to be before or after Tokyo.

"It was a bit different and a bit easier on the body in some ways, but I also think it's been really good mentally for me to have had a bit of a different focus."

Brownlee said he was pleased with the recognition afforded his sport after being chosen to be England flag bearer.

He added: "Growing up watching major Games on TV it was always a big deal to me who was carrying the flag, and I never in a million years thought a triathlete would get to do it."