Evolution of groups of gravity waves with moderate to high steepness

Experimental measurements of evolution of a deep‐water wave group are described. Wave groups are found to change rapidly over a few tens of wavelengths when the initial steepness 0.09≤a0k0≤0.28. The transition creates envelope solitons composed of waves with smaller steepness and lower carrier frequency than the initial state. The carrier frequencies of the envelope solitons can be downshifted as much as 25%. The transition process is irreversible, but does not lead to total randomness.