A while ago I posted two photographs of (more or less) the same feature on one of the Smitswinkel Bay wrecks, taken one after the other. On one the flash fired, and for the other I turned the flash off. The idea was to demonstrate what the absence of light at depth does to colour.
Here’s another example of the same phenomenon, taken on the SS Maori at about 15 metres’ depth. The water was very clear, but the red algae growing on the pipe had lost much colour even at that depth.
