Figure 4: (a) Streamerwise imaged sea surface covering the same area as in Figure 3(a), (b) the same sea surface as in (a) but with the mean of each sea surface profile subtracted, and (c) the spectral plot of the imaged sea surface shown in (b). The indicated peak of the spectrum in (c) corresponds to and . The imaging technique was applied in 2D (i.e., streamerwise with each streamer taken in the inline direction).