John and Tim begin their epic journey in the upper reaches of the tributaries that feed into the Murray and Darling rivers. Our intrepid adventurers make a futile attempt to launch the Bismarck on the Maranoa River, only to find their launch spot is bone dry! Maranoa, they later discover, means 'river of sand'. Finally there's enough water in the Balonne River to get the tinnie wet, but there's a question over the seaworthiness of the mighty vessel. Making their way down to the Queensland/NSW border, they wander through the parched, brown landscape inspecting the river red gum forests that are dying of thirst, and also uncover the age-old water controversy that people downstream are dirty on people upstream. And that means everyone's dirty on Queensland.

Continuing their journey along the Murray and Darling rivers, First Mate John Doyle and Captain Tim Flannery decide to trace the journey of Henry Lawson who worked on the sheep station, Toorale, in the 1890s. After examining its grandeur, Tim and John bunk down in the shearers' quarters for the night. John and Tim navigate the Bismarck along what's referred to as the 'muddy gutter' of the Darling to Louth, where they bump into Wally Mitchell, farmer, bush poet, former Mayor of Bourke, and a bloke familiar with the squabbles over water. After travelling for weeks down a river whose chief feature is lack of water, John and Tim reach the vast storage of Menindee Lakes in western NSW. Suddenly there appears to be water everywhere. Just downstream on Lake Menindee itself the residents of dry and dusty Broken Hill, an hour west, have built their waterfront weekenders. But there's a minor problem. So little water flow is getting past the dam, there's been no water in Lake Menindee itself for years. But a dry ancient lake can reveal the most extraordinary secrets, especially if you have a palaeontologist's pick on hand. After the excitement of their find, John and Tim call in to visit the ladies of the Country Women's Association for a good dose of local wisdom and a cuppa. But the river calls and there are a few more stops along the way.

John and Tim have begun to appreciate they are travelling down one of the world's longest river systems. Unfortunately it has one of the lowest flows. On the Darling itself the two adventurers have been hopping from water hole to water hole in the Bismarck. The Bismarck navigates through a slimy, weedy part of the river that's choking on blue green algae. The outbreaks of the algae have been so toxic, they've killed sheep that have come to drink the river's water. Looks like the Bismarck could be its next victim. After 2,000 kilometres and nearly four weeks on the river, John and Tim approach Wentworth in south west NSW, where the Darling meets the Murray. A river with lots of water is a novelty for the Bismarck. John and Tim decide to haul out the Bismarck and travel by road from Swan Hill to Albury, then up into the Snowy and the beginnings of the mighty Murray. After the dry and dusty Darling, suddenly there's lush, green grass and water. It's like another country. It's where Banjo Paterson met Jack Riley - the real man from Snowy River. But where there's more water, there's more people and more boats, and of course, more idiots. The Bismarck is unceremoniously swamped by jet skis, inspiring John to propose the creation of a Water Party that would ban all jet skis! After trying their hand at traditional Aboriginal spear throwing, John and Tim want to get a handle on the unwelcome guests that have infested the Murray - carp. Carp are the rabbits of the rivers and are wiping out the native fish. "Too many carp. Not enough cod. Too much weed. Not enough water. It's a grim tale", says John.

After the stop/start progress down the Darling, John and Tim find the Murray a veritable speedway. Tim winds up the Bismarck to full throttle; the mighty tinnie's never been faster. They declare it's a joy being on a river with water in it. After four weeks, our unshaven adventurers head east of Albury to the Barmah Forest where the renowned red gums and wetlands are dying of thirst. John and Tim looked at cotton irrigation on the tributaries of the Darling, now down on the Murray they take a look at rice farming near Renmark. To John it seems an absurd pursuit in the world's driest continent. After 4,000kms, gliding down exhilarating sections on the lower reaches of the Murray, John and Tim make good time before beaching the Bismarck and camping on the NSW/South Australian border. At least they think they do. A peculiar quirk of mapping has them very confused about whether they're actually in NSW or South Australia. With the Bismarck motoring beside spectacular cliffs on the banks of the Murray, Tim, otherwise known as the 'Indiana of Stones', sees things in the rocks and the land that the average person misses. A rocky cliff that looks an obstacle to getting ashore proves a potential treasure trove. After digging away at one cliff face, Tim finds fossilised coral and an ancient shark tooth, proving that the floor of the ocean was once here. John, too, appears to be developing a growing passion as a 'fossil hunter'.

After 40 days on their journey, John and Tim undertake the last leg of their adventure, travelling down the lower reaches of the Murray. To make good time they often rise early and power along the glossy waters before the wind gets up. Some mornings with the dawn sun playing on the water and trees, they turn off the motor and drift downstream taking in the sights and sounds of life along this mighty river. On day 46 the duo reach Lake Alexandrina, a lake so vast it feels like the ocean. But with an average depth of just three metres it can become very precarious for unwitting travellers and many a sailor has come to grief. All of a sudden the tinnie feels very small and when the wind comes up, John and Tim make a hasty retreat to the shore. Finally the Bismarck reaches the end of the Murray. On one side is fresh water, on the other side is the brackish water of the Coorong. This is Storm Boy country. After being ushered through many locks and weirs, this is the first lock that John and Tim are required to operate themselves. Luckily they don't have a deadline to meet! At the famous Coorong, the Murray takes on a completely different character. Since beginning their journey, John and Tim have travelled from the tributaries of the Darling all the way to the Murray. Then from the beginnings of the Murray all the way to the sea. Now they can smell the ocean.