This photo was taken at a beach in Santo Domingo, a Northern Philippines town. This is our native hometown and the family had a chance to visit it when we went home for a wedding before the pandemic lockdowns, Our house is close to the beach so one morning we hopped in the motorbike (I was not the driver, just a back rider) and off we went. It isn't a white sand beach nor grand, but it is still a nice one to breathe fresh air and walk barefoot. The ticklish feel of the sand on bare feet is a natural therapy.
I grew up believing that the ocean is blue because it is reflected from the blue sky. But I learned that this is not so.
The ocean is like a sunlight filter. In the sunlight spectrum, red has the longest wavelength and blue has the shortest. In the ocean or water, the color with the longest wavelength which is red is strongly absorbed. So when the light from the sun enters the ocean, red is quickly absorbed and blue having the weakest absorption is the one that gets returned or reflected. Blue is the color that we get to see in the ocean.