This is a unique situation and a lot of luck, because this small whitetip reef shark was trapped and hidden in a formation of hard coral Acropora sp.
I managed to do only a serie of three photographs before finish the air and he was still there on the spot.
This one was made more closely, about 50 cms from the eye of the shark and using the Anthis wet diopter in the flat port.
In this type of photo contest is not allowed to change the photos and then have to send the original RAW to make the photo in large format for display in the magazine and in the museum.
Thanks, I figured as much after looking at the settings for the camera. With that f/stop and DOF I figured you had to be very close. At least I think that logic makes sense. You guys are teaching me a lot and I am very thankful for all the help.