Three snorkelers were posing for a photo while on holiday in the Cayman Islands when the creature suddenly appeared behind them.
They were reportedly taking part in snorkelling day in Stingray City, a tourist spot where visitors can feed and touch the fish.
Stingray City's website states: "Enjoy this unique experience of touching and feeding a stingray, together with snorkelling amongst magnificent coral reefs and colourful tropical fish.
"Standing in only three feet of water, you will be surrounded by more than two dozen friendly stingrays."
The photograph was posted on Imgur, and quickly became an internet hit across different social networking sites.
One Twitter user described the image as "the photobomb to end all photobombs".