Underwater photographers have to be prepared for almost anything, and they realize their powerlessness on a dive. They depend on each other below the surface, as does this husband-and-wife team.

I don’t want to give too much away, but ask yourself: When danger approached, would you warn your partner or get the photo? Here’s Jennifer and David’s story:

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Originally published in February 1956’s National Geographic, this image by Luis Mardencaptures