Ocean waves are Liquid waves. Also known as surface waves. Surface waves are the only ones in physics which show dual propagation, transverse and longitudinal, both at the same time. The only ones in the whole nature, in fact, with dual propagation.

Wave propagation, whether transverse or longitudinal, in this very case BOTH simultaneously, is ONLY mathematically possible when waves are travelling on a STRAIGHT LINE, known as still water level or equilibrium line.

This is due to a …