After enjoying the tranquillity of the paradise islands of Koh Phi Phi, the teams now face a giant leap into the unknown, leaving Thailand behind to embark on a 2,000km journey across Malaysia to the rarely visited Indonesian island of Sumatra, where the sixth checkpoint lies in the mountain-fringed city of Bukittinggi. Our intrepid duos will need to decide whether they want to island hop via Koh Lipe, maximising their time on Thailand's white sandy beaches but likely to put a strain on their budget, or go back to the Thai mainland to make the most of cheap and frequent transport links down the Malay peninsula. At this stage in the race, with budgets dwindling and the pressure mounting, every decision counts.