The first stage of the journey from Rurrenabaque to the pampas is quite an ordeal. First you have to drive for three hours in a jeep, which should probably be scrapped, in extreme heat along a dirt track with dust assaulting your face in great gusts every few moments - no good for asthmatics. I felt the grumpiness of the driver was necessary to complete the package. He wasn't a patch on the tour guide who met us at Santa Rosa though to accompany on the next leg of our journey - another couple of hours in a boat - and look after us for the next three days. Victor was rude, patronising, authoritarian, generally stoned and/or drunk, sleazy, uninformative and altogether disagreeable.

This didn't stop us from having an absolutely incredible journey up the river. In every field of view were caiman (alligator-like creatures), caipiburas (sheep-sized rodents), herons and other beautiful birds ("Gosh we're all pretty impressed down here"), the highlight by far being squirrel monkeys. We pulled over to the bank to wach dozens of our yellow, fluffy cousins edging towards us through a tree on the bank, curious to see us, and, presumably, our food. After about five minutes of cautiously eyeing us up they seemed confident that we posed no threat, and one by one jumped into our boat, one running up my arms and then briefly settling on my legs. I couldn't believe how soft their human-like hands and feet were.

An hour or so in we noticed some smooth, greyish-pink humps (not what you think), periodically emerging from the water surface for a second or so before sliding back under. We briefly scanned the river for caiman eyes before changing into bikinis and jumping in to join the dolphins. For about half an hour in the filthy Amazon water they played chase with us, and tug-of-war with sticks (one end in one of our hands and the other in their mouth), before we bid goodbye and clambered back into the boat.

When we arrived at camp - a complex of wooden huts on stilts, connected by ramps - Victor pointed to our hut, announced dinner time and disappeared. We didn't mind. At dinner he reappeared to spew out some rules - utterly bizarre within the context of a tour - namely no crying, shouting, screaming or being late. The last turned out to be highly hypocritical as he was frequently too drunk to turn up for things on time. After dinner we took a night trip on the boat to flash our torch light on the eyes of poor caiman to see them glow orange. Victor was stoned. Ten minutes in we passed a number of other boats whose guides had captured baby caiman for their group to see, causing us immediately to break Victor's rule about shouting - in particular Sophie, a lovely vet in our group, who shone her torch at them and yelled at them, "You should be embarrassed". Victor suddenly got uncontrollably panicky, pleaded that we turn off the lights and stop shouting, and urgently drove the boat downstream away from the other groups. There in the dark he begged us all not to tell the tour agency what we'd seen.

I was ill that night and went to bed as soon as we got in, exhausted from arguments and generally weak. My hopes for sleep were disrupted by a drunk asbo scouser who insisted on shouting loudly outside our door despite numerous polite requests from our room that she go elsewhere or be quieter.

The following morning we walked in the scorching heat for about half an hour to some boggy marshland, and waded through it with sticks in search of anacondas. Some of the group managed to find one, and we stumbled across a dead cobra, but it wasn't a terribly rewarding exercise. Part way in I started to feel weak, and got rapidly more ill as we made our way back to the boat. I couldn't sit up by then, and when we arrived back at the camp Clara had to help me walk to the hammocks. No big deal, but again there has to be a Victor-related catch. As Clara explained that I was feeling nauseas and faint, he pushed my hammock back and forth like a ride at a fairground, clearly greatly enjoying himself - clearly stoned. I stayed at the camp to sleep after lunch while he and the rest of the group went fishing for pirahnas and catfish. I awoke when another group of travellers came into the hut to occupy the neighbouring hammocks and again play the rocking game, swinging into each other (and me) with domino effect. This didn't help either.

By the following morning everyone was so fed up with Victor, and one of the girls in particular made to feel thoroughly uncomfortable by his passes at her, that noone felt enthused by the plan of swimming in the river with him again. Instead he just took the boat to the place on the river at which we would have been swimming and we sat there for an hour while he went to talk to a caiman named Peter Crouch. We returned in time for an 11am lunch before leaving for Rurrenabaque. Before parting with Victor we discussed with him our disappointment that there had seemed to be such problems with social relations, and again he asked us not to tell the company, a request which we decided not to honour.

Back in Rurrenabaque Clara felt ill (not the same kind as me) by which time I'd recovered, and so nursing roles were conveniently reversed. We had a "last supper" with our lovely tour group, minus a couple who'd already left for a flight, and had another early night. In the morning we woke at 5.30 for a planned 7.20 flight back to La Paz which we were told had been postponed owing to low visibility. The plane never turned up and we were put on the 9.30am flight instead: blatently they just couldn't be bothered to run the earlier one for only four passengers. Poor, ill Clara could have done with the extra hours in bed.

We spent another day and a night in La Paz for hopsital visits before getting the all-clear to move on to Lake Titicaca.