Up until the ‘60s, the major advances in diving technology were driven by big-budget military programmes. Extending the depth limits to which divers might safely go—and still be capable of performing meaningful work when they got there—had a practical purpose. David Strike has the story, as told by George Wookey.

Many people suffer from ear problems during and after diving. Technical rebreather diver and underwater photographer Dr. Michael Rothschild is an ear, nose and throat specialist in New York City. In this series, he walks us through some of the common causes of dive-related ear problems, and how to treat and prevent them.

Kate Jonker is an award-winning underwater photographer and coach, internationally published writer and public speaker, dive boat captain and dive guide based in South Africa.

We asked our contributors what their favorite underwater photos were of the legs, arms or tentacles of critters underwater. And they came back with a variety of subjects from curious crustaceans and cephalopods to jellyfish, sea stars, feather stars, frogfish and even people underwater.