Figure 1.  Can you you see a fish in this photo? This is a frame grab from a video uploaded by jamesnahon in YouTube showing how they prodded an excellently camouflaged stonefish to swim away from them.

See the video here: http://www.youtube.com/watch?v=OczlPLNboME.

Figure 2. A frame grab from the same video showing the stonefish revealing itself after being disturbed by the diver's instrument.

Figure 3.  A frame grab from the same video showing the stonefish swimming away...a rare sight indeed.