The bar formed by the river where it enters the sea, 6km further downstream, is impassable. Navigation alternates between wide deep river sections and 11 diversion canals, and bears no resemblance to that immortalised by Bernard Clavel in Lord of the River.
This route is preferable in any case, with the numerous facilities offered by this small town. The route description gives these distances, since they are visible on the banks. At the end of each diversion canal we give the difference between the apparent distance and the actual kilometres covered since the diversion canals are shorter. Channel improvement works between and increased the low-water navigable draught to 1.
The 12 hydroelectric plants and locks were built between and The landscape of the diversion canals is often bleak and austere, but efforts are being made to improve the environment of the river and its banks, especially in the main towns.
The distance table gives the actual distances, allowing for the shorter diversion canals. It has been tamed by the big dams and their accompanying diversion canals. The mistral northerly wind can make lock entry difficult from upstream. The channel is marked in places by red-and-white buoys or stakes on the right-bank side and more rarely by black-and-white markers on the left-bank side. Life-jackets must be worn in locks β this sensible rule is rigorously enforced. The phenomenal engineering works detract only slightly from the beauty of the valley, which runs between the foothills of the Massif Central and the Alps.
All except Vaugris are situated on diversion canals, and are adjacent to the hydropower plants. The layout is such that the entrance is in many cases not clearly visible until the last few hundred metres. Enter only when a green light is showing. The fall varies between 6. All locks are fitted with floating bollards. Single boats are locked through if no commercial traffic or other boat appears within 20 minutes of arrival at the lock.
