In practice, canoes are really equipped with 2 seats, located at the front and rear: these are the so-called normal seats. They can be occupied by adults, or by an adult and a child aged 7 and over.
The 3rd center seat is therefore a seat located between the two normal seats, and can only be occupied by a person weighing 35 kg maximum. This unconventional but very practical place for groups and families benefits from a single preferential rate for all descents, except for descents with bivouacs.