A Tidal Bore, in Indonesia (precisely in Riau) is called as Bono. This is a tidal phenomenon in which the leading edge of the incoming tide forms a waves of water that travels up a river or narrow bay against the direction of the river. As such, it is a true tidal wave and not to be confused with a tsunami, which is a large ocean wave traveling primarily on the open ocean.
Riau people said the Bono in Kampar river as a ‘Seven Ghost Waves’. The word bore derives through Old English from the Old Norse word bára, meaning “wave” or “swell”. A tidal bore may take on various forms, ranging from a single breaking wavefront with a roller, which is like a hydraulic jump to “undular bores”, comprising a smooth wavefront followed by a train of secondary waves . The large bores can be particularly unsafe for shipping but also present opportunities for river surfing.
The tidal bores may be dangerous and some bores have had a sinister reputation, but in some moment, during the tidal bore, a river will be way more interesting for tourism interesting. This case may refer to the interseting wave that can be used for surfing.