Diving alongside playful sea lions can be a thrilling experience. Here's what to expect—and how to snag the best photos.

Open-water certification is great, but the destinations on our list are best visited after mastering some advanced training. Here are six sites where extra certification goes a long way.

April 25 is World Penguin Day. To celebrate, we’re exploring the world of these wonderful waddlers–from what makes them fun to why we need to protect them.