The very first attempt at underwater photography was by William Thompson in Dorset, UK, who in 1856 used a wet collodion glass plate camera to create the photo.
In 1893 French zoologist Louis Boutan shot the image listed as the world’s first true underwater photography.
It was a first both in terms of being the first underwater photograph, where both the camera and the photographer were underwater. It was taken with a magnesium powder flash.
It was also the first published underwater photograph. Some sources claim that the portrait was captured at a depth of 164 feet.