During a walk along the marine drive at Scarborough I noticed two distinct sets of plane wavelengths as well as a lot of other bits. the main swell had a wavelength of maybe 10 metres but there were other waves that seemed to be nearer 50cm. The swell was clearly reflecting intact. It reminded me that the sea must be a superposition of many frequencies of disturbance. If it were a sound, it wouldn't be very harmonious. The deconstruction of such a mess into component frequencies is done by Fourier Analysis. I felt as though I'd caught a glimpse of what this actually means.