A rosy dawn has given way to crisp daylight when we arrive at the boat ramp at Corroboree Billabong, 150km east of Darwin. Rowdy cockatoos squabble in the eucalypts and wallabies watch warily from nearby grasslands as Trevor Robb, our guide from Darwin Barra Fishing, eases the boat into the water.
Along with Timo from Finland, my husband and I have joined Trevor for a day chasing Australia's most prized sporting fish, the barramundi. The billabong - which has 42km of navigable waters and is part of the Mary River system - is also known for its prolific wildlife, especially saltwater crocodiles.
We've just motored away from the boat ramp when a 3m beast rears out beside us, churns the water with a swish of its tail, then disappears into the depths. Others float with eyes just above the surface and sink out of sight as we approach, while some lie watchful on the banks.
Further on, Trevor points out a sea eagle perched in a riverside tree, a lanky jabiru shading its young with outstretched wings, and whistling kites soaring overhead. Large flocks of magpie geese line the banks, and jacana - also known as Jesus birds or lily trotters - seem to walk on water as they tread lightly across lily pads where pink and purple flowers flare against the green. By the time we stop to fish, we've added brolgas, darters, spoonbills and sacred ibis to the birding list.
Barramundi are voracious predators that hang around submerged rocks and logs, so we begin trolling with plastic lures, feeding out lines and letting them sink deep while Trevor manoeuvres the boat slowly forward.