In 3 days to the sea

With Yuri, Stefan and Dirk taking turns as navigators, we head for the sea during the next 3 days. Tapping running water from a small stream in the forest is not a problem at all, being far from the land of the living there is no pollution. One of the many learning objectives is to fix the tarpaulin in a solid way, later on this will appear to be a lot more difficult at the beach. At the beginning of the third day, while the sea is already audible, we reach the river, which is between the beach and the forest. It is bounded by much mangrove. Zico is checks if there is a fordable spot. No way. So what now?