  Wave turbulence in quasi-1D geometry is usually not investigated
experimentally since low-order resonant wave interactions are theoretically
prohibited. Here, we report on the first observation of unidirectional
capillary-wave turbulence on the surface of a fluid in a canal. We also show
that five-wave interactions are the lowest-order resonant process subsisting at
small scales, and are thus probably the one generating such quasi-1D capillary
wave turbulence. We show that the wave spectrum is compatible with the
corresponding dimensional analysis prediction. The main assumptions of weak
turbulence theory are also verified experimentally. Quasi-1D wave turbulence
could be thus highlighted in other fields of wave turbulence.
