Bono or bena (English: tidal bore) is a wave or waves that occur at the mouth of a river such as in the Kampar River, Pelalawan Regency, Riau Province, Indonesia. Bono waves are a natural phenomenon caused by the meeting of river currents towards the sea and sea currents that enter the river due to high tide. Waves that are quite large are widely used for surfing. The biggest Bono usually occurs during the rainy season when the water discharge of the Kampar River is quite large, namely around November and December