Three-dimensional surface shapes of breaking waves were quantitatively measured using a novel imaging technique with a projector and digital camera. With a measure of relative surface length, three-dimensional transitions of the deformed wave shapes have been characterized for spilling and plunging breakers. Two kinds of jets, a so-called finger jets, deformed due to sub-surface turbulence, and preceding smaller jet, governed by surface tension, have been observed to predominate the splash-up cycle in the surf zone, which have distinctive lateral and longitudinal length scales as well as deformation velocity scales evolving in breaking process.
