Section length: 19 km (+ 1 km Krępiec, Motława)
The kayaking trip on this section is very exciting as there are as many as 4 historical hydroelectric power stations on the route. The river between Straszyn and Pruszcz Gdański is not challenging, but very charming. It flows through lush greenery, with fallen but harmless trees, offering nice views, while its light current makes your trip easy and pleasant. The only difficulty may be portages. The trip starts at the lower power station in Straszyn. Initially, you follow the river among forests. Then you reach a backwater area with a portage at the Prędzieszyn power station. Further on, the river flows among trees growing by its banks, but the nearby land has already been urbanised. Another backwater, and you arrive at the Kuźnice power station. One more portage and the route follows a regulated riverbed and then changes into the Juszkowo reservoir with another portage at the power station. The route runs alternately across meadows and built-up areas, with trees spreading along the banks. You pass under a road bridge on the expressway and approach Pruszcz Gdański. There is a fork in the river: to the left, you can see the Radunia Canal, which conveys water to Gdańsk (not suitable for kayaking due to low water levels), and to the right, there is the old riverbed. Right next to the Trading Post (a reconstruction of a settlement from Roman times), there is the last hydroelectric power station on the Radunia River. You have to portage along the left bank through the Trading Post. The next 2 km take you through the town of Pruszcz Gdański. At the former sugar factory there is a portage – a concrete water threshold. Further on, the river speeds up a bit (Św. Wojciech) and then becomes lazy as you enter the Żuławy region. Now you follow the wide riverbed among fields and meadows and the embankments overgrown with reed until the route reaches its mouth at the Motława River. The trip can end in Krępiec (about 1 km upstream on the Motława River, weak current) or continue down the Motława River to Gdańsk (6 km).