Denhaut got his license in 1911 in a Fernandez biplane; and while chief pilot at Pierre Levasseur's flying school in 1911 he conceived of a new form of seaplane, this with a hull instead of floats. The hull was triangular in section, with the point at the top; a small forward planing surface was placed close to the water under the bow. The lower wing was set above the hull, overhung by the upper wing. The 50 hp Gnome, donated by Swiss engineer Jacques Donnet from his unused Bleriot XI, was set between the wings with a pusher propeller. A temporary 2-wheel landing gear allowed the machine to take off from the ground; all of which worked well. On his first attempt to land on the water, Denhaut turned the machine over. The second machine had a pronounced step in the bottom of the revised hull, and no forward surfaces.

   (First version: span: 9 m; length: 8 m; weight: 300 kg; Levasseur propeller; 50 hp Gnome)