Sentinel 2 imagery
Optical images of the ocean surface offer stunning views of ocean waves including whitecaps and other features. You can go to the [ https://twitter.com/Sentinel2Bot | S2 bot ] for a wide range of examples. The data can be dowloaded from the [ https://scihub.copernicus.eu/dhus/#/home | Copernicus Science hub ], you just have to register.
The MSI sensor uses 13 "channels" (think of them as "colors") and series of 12 detectors, each detector acquiring teh 13 channels and each with a slightly different view geometry. The small differences in acquisition time and view geometry between the channels and detectors can be used to look at things moving on the ocean surface.