Exact and quasi-resonances in discrete water-wave turbulence

The structure of exact and quasi-resonances in water-wave turbulence is studied. It is shown the number of exact 4-wave resonances is huge (hundreds million) even in comparatively small spectral domain when both scale and "angle" energy transport is taken into account. It is also shown that angle transport can contribute inexplicitly to scale transport. Restrictions for quasi-resonances to start are written out explicitly. The results can contribute to short-term forecast of wave field evolution.