Galapagos is famous for its schooling hammerhead sharks. However, these sharks don't seem to like the divers' bubbles. I needed to hold my breath until I was almost going to pass out waiting for this hammerhead to swim over me for the silhouette photograph.
Robert Yin has taken underwater photography from a hobby to a life-long professional career with extensive publication in books and magazines. His most recent projects include a series of twenty children's books "Marine Life for Young Readers" published by Dominie Press.