"When does the boat get to Manaus?"

"Wednesday. Or Thursday. Maybe Friday."The n/m Onze de Maio sails an hour late, which probably counts as early in Brazil. Sleeping accommodation is bring-your-own hammock. Steerage passengers share the engine/cargo deck, most of the rest eat and sleep on the middle deck, and the lucky few are on the top deck with the bridge, the bar and general hanging out.

In the morning I wield the Bangkok kettle to maintain my caffeine level. Small dugouts piloted by eight-year-olds skim across the river and attach themselves to the boat using grappling hooks, and the kids clamber aboard to sell shrimps and fruit.

Toucans flit among the trees; there are egrets, sometimes riding the backs of water-buffalo; ordinary-looking sparrows and finches; carrion-eaters like vultures; bird-sized flying insects; huge dragonflies; and pink dolphins.

The settlements along the riverbank all have satellite dishes and churches, as well as schools. Everywhere people turn and wave, and the kids race in their canoes to ride the swell of the wake. One of the larger boats is called Princesa Dayana.

Many of us pass the time playing canasta and dominoes. Diego and Andreas are the Colombians I saw riding Honda 125s on the road between Fortaleza and Belém. We join forces as they want to learn English and they speak more Portuguese than I, and of course we talk bikes a lot. Gonzalo from Santiago and Daniel from Novi Sad join in as they're both motorcyclists as well. When the boat stops at Itacoatiara the police come on board with a sniffer dog. I blame my boots, which I've locked in the topbox; all three of us have to completely unload our bikes and itemise absolutely everything to the police. Normally I like black labradors, and actually this one is rather sweet in his uniform, especially when he refuses point blank to descend the companion ladder to the cargo deck and has to be carried in the arms of a rather sheepish-looking copper. All rather a pain, though.

Then later the peripatetic chiropractic comes up to the top deck and gives my joints a jolly good seeing-to, after which a well-earned cachaça hits the spot. Tonight's canasta session involves British, Brazilian, Israeli, Colombian, Chilean, Peruvian, German and Serb, and gets into three-pack territory.

We dock in Manaus in the early hours of Thursday. Up at six to throw luggage on to the dock and manhandle bikes up from the cargo deck. We help Simoãa and her scary mum with their bags, including their new duck sitting happily in his very own plastic carrier bag.

And then I ride past the astonishing Opera House, and find I've managed to arrive in the middle of the annual Amazonas Opera Festival; so on Sunday I'm seeing Verdi's Otello. What a treat.