Jase and Simon head down the track to Captain Billy's Landing with the goal to head up the beach to find a secret waterfall. They are greeted by windy conditions and a sandy track down to the beach. Once they get to the first headland, they go from sand driving to rock crawling and can't afford to get stuck with the returning tide. They make the call to turn back with the trucks until they have a dropping tide to give them a bit of extra time to pass the headlands. So they take the buggies down the beach to explore and see what has washed ashore. Then it's back to camp for a cook up finished off with some caramel dumplings. The next morning they set off up the beach again with an outgoing tide to give them some more time to navigate the boulders dotting the headland. They do some landscaping with winches to clear the path for the trailer and to get up and down the rock ledges. Back to the sand above the high-tide mark, Simon manages to get himself stuck. They also make the call to scout ahead in the buggies and determine whether they'll make it to the river in the trucks. The big trailer gets left on a dune to save some effort dragging it to the river. The boys get out the inflatable boat to head upstream not knowing how soon they'll have to portage through the shallow spots. Evidence of crocs puts everybody on edge, especially as they set up their rustic camp for the night. The next morning it's an early start with high tide filling the river basin. Eventually, they ditch the little boat and finish the trek on foot. The water is clear, but Simon spots a big black croc which inspires a change of direction. So they head for the hills to steer clear of the wildlife, but it's slow going and hard terrain when you're wearing thongs. Back in the low country, they follow the river through some beautiful pools and eventually they find the promised hidden waterfall. A perfect spot to shed a layer of dirt!