The Torus channel is an evolution of the Zero Slot Hull Channel, and one of the newest bottom contour innovation's.
This is a variation of the planing hull, whilst being mindful of the drive and hold required on a bodyboard.
On the torus channel, the wider points of the centre channel are at the nose and the tail of the board. This allows water to be welcomed into the channel then squeezed through the narrower centre point at a greater speed, before released through the slight concave in the tail at a reduced pressure, much like the Venturi effect.
This creates extra lift and drive from your shoulder / elbows, while still allowing plenty of hold through your hips.
By having a long, but subtle channel such as this, it also means we need less channels on the slick to keep the board holding in.
Fun fact: if you were to continue drawing the lines of the channel off into the spaces of the board, they would eventually loop back into themselves to make the torodial shape.