The Wobbegong, a species of carpet shark, stays motionless most of the time, and this individual was surrounded by a myriad of glassfish.
It wasn't the first time I came upon this sort of cohabitation in the waters of Fish Rock island (South West Rocks, Australia) but that day surge could be felt at the 27 meters depth where the shark was located.
I decided this was a photographic opportunity worth pursuing, timing my shot precisely when all the fish would face the camera, as they swim against the surge. This also was the best angle to shoot these "glass" fish without over-exposing their reflective body with strobe light.
It took me several attempts, until I got the timing right.