17-Sep-2003 -- This confluence is close to the main highway from Cuiabá, Mato Grosso to Porto Velho, Rondônia, on the section between Comodoro, MT and Vilhena, RO. Angelina and I planned to attempt it while visiting our friends Menno and Barbara Kroeker in Vilhena.

What we didn't know until we got there was exactly how far it was from the road, or what the terrain would be like. While taking the bus to Vilhena, we made a preliminary assessment. The good news: the confluence point was only 1.25km from the nearest point on the road. The bad news: although the majority of the land along the road has been turned into farms, this part was still jungle.

When we had a closer look by car, I was resigned to taking a photo of the nearest point on the road and recording an incomplete visit. But Menno and Barbara had other ideas. They produced three machetes, and off we set to hack our way through the jungle.

Navigation was not always easy. In complete contrast to our previous confluence visit, the GPS sometimes had trouble locating enough satellites to give a reading at all, and at other times it would jump around by tens of metres. Additionally, we were walking so slowly that it refused to recognise our direction of travel. So most of the time, we just followed a constant course on the compass (or at least, as constant a course as possible — it isn't possible to walk in a straight line in the jungle!).

It took us over 3 hours to cut a path the necessary 1.25km, but we did eventually reach the required point. This point read "all zeros" when we arrived, but it jumped by 7m before taking the photo. The EPE here was 10m, giving a total accuracy of 17m. The altitude given by the GPS varied quite a bit, from 584m to 612m while we were standing there.

Having reached the confluence point, we took photos North, South, East and West, though our whole route looked much the same as these. We also took a group photo. We didn't hang around long because ants and other insects had discovered us.

The trip back to the car was much quicker and easier — it only took 80 minutes because we were able to follow our own trail back again without too much difficulty.

Many thanks to Menno, Barbara and Angelina for being more game than I was, and to Patrick Gosling for the loan of his GPS.