He was carrying a 40lb backpack, tripod, camera, several expensive lenses and a pack of rather soggy Jaffa Cakes for sustenance.
It was his final week of a month-long trip that he'd planned and funded himself almost seven years ago, and he'd lost nearly 2st lugging his kit through the rainforest.
'It was really gruelling — like something from the SAS!' he says today at his home in Chepstow, Wales.
His aim was to photograph animals which were endangered, and use the images to draw attention to their plight.
The Holy Grail was the very rare crested black macaque — a critically endangered monkey with an entirely black face that is found on just two Indonesian islands.
'There were only a few hundred left and I'd only ever seen a photo of one,' says Dave.