Here's another shot from that dive at Point Lobos. This guy is some sort of rock cod (maybe ling cod?) that I ran into at about 30 feet. Continuing with our discussion on interesting camouflage techniques, here's a cool example. Notice that there's a lot of red in this photograph. The coral is red, the fish is red, even those weird little shellfish stuck to the rock are red. A common thought would be that since everything is red, the fish must be camouflaged; however, that's not exactly the case. We tend to think of red as a very obvious, stand-out color; but under water, it's a very different story. If you want to hide under water, red is a very good color to be. Here's why:
Red light dissipates faster than blue light.
Have you ever asked yourself (or, more likely, have you ever had a five-year-old ask you): Why is the sky blue? Why is the ice blue? Why is the ocean blue? Why is the lake blue?
Is air blue? No, air is clear. Is water blue? No, water is clear (see comment). So why does it look blue? When the white light from the sun passes through a clear medium (like air or water) the low-frequency spectrums of light (reds) get absorbed quickly while the high-frequency spectrums of light (blues) get absorbed more slowly. Hence, the blue light is the light that you tend to see. The denser the medium, the shorter the distance required for this to noticeably take effect.
So when sunlight passes through 30 feet of sea water, by the time it hits a red fish, there's very little red light left to reflect. The fish is essentially hidden.
When air is the medium that the light is traveling though, it takes a much much longer distance for this to take effect... miles, not feet. That's why red sports cars get more speeding tickets.
So, there's one more unanswered question: If there's no red light left, why did my photograph turn out red? Easy: I introduced new light via a flash, and since I was only a couple feet from the fish, the red light didn't have a chance to dissipate.