Complex sentence: It is a well-known river surfing destination because of its tidal bore known as Bono, caused by sea water from a high tide flowing upstream into a wide, shallow, and rapidly narrowing channel against the normal flow of the river water.
Split into simpler sentences: It is a well-known river surfing destination because of its tidal bore. Know as Bono, it is caused by sea water from a high tide flowing upstream into a wide, shallow, and rapidly narrowing channel against the normal flow of the river water.