rivers are typically steep pool-drop rivers with many waterfalls, and are run mainly by experienced kayakers. There are also bigger (sometimes glacier-fed) rivers which are sometimes rafted. The season lasts all summer, although some rivers only run after recent rain. Norwegian waterfalls regularly feature on extreme kayaking videos. Portugal The best time for whitewater in Portugal is in Spring during the higher river flow. Paiva River - Praia do Vau to Espiunca, Arouca, Class 3-4 Laboreiro River I - (Castro Laboreiro) Ameijoeira Bridge to Ribeiro de Baixo, class IV-V (X); Laboreiro River II - (Castro Laboreiro) Ribeiro de Baixo to Olelas, Class IV-V (X); Vez River I - Porta Cova (Sistelo) to Sistelo Bridge, Classe IV (V); Russia White water sport in Russia is quite popular, but the vast majority of people uses catamarans for these purposes. The best period for whitewater is May and July–August. Some rivers are possible to raft in June and September. Here is a list of the most popular rivers: Altai Peschanaya river - Class III Katun river - Class IV. One of the most volumed river in the region. Kumir, Korgon, Charysh rivers - Class IV. Normally, the trips include rafting down all three rivers. Chuya river - Class V (VI for Mazhoiskiy kaskad). The right tributary of Katun river. There are regular competitions down Chuya on the Mazhoyskiy kaskad part - the canyon part of the river, which includes around 30 rapids, 10 of them are VI class. Bolshaya Sumulta, Malaya Sumulta rivers - Class V. Malaya Sumulta flows into Bolshaya Sumulta which is the tributary of Katun. Shavla river - Class V. Tributary of Argut. Chulyshman river - Class V (VI). The middle and down part contain three rapids V class and two VI class. The upper part contains seven VI class rapids. There is an opportunity of rafting down upper Bashkaus and middle-down Chulyshman (Class V). Bashkaus river - Class V (VI). The upper part has a number of IV class rapids and one V class. The down part is one of the most difficult places for white water containing 11 rapids VI class. The river flows in 35 km canyon without any opportunity of evacuation by land. Argut river - Class VI Kadrin river - Class VI Baikalia Zun-Murin river - Class III Utulik river - Class IV (V) Khara-Murin river - Class IV (V) Snezhnaya river - Class IV