Underwater photographer David Doubilet made his first trip to Australia's Great Barrier Reef in 1979. Since then, he's returned 11 times to the 1,400-mile-long (2,254-kilometer-long) kingdom of coral off the Queensland coast.

In light of news that the United Nations may add the reef to the list of endangered World Heritage sites, editor at large Cathy Newman spoke to Doubilet about his encounters with the reef and its uncertain future.

You've made 12 trips to the Great Barrier Reef over the past three decades. What do you remember about your first trip?

I had my first encounter with a sea snake. A big olive-green one came up and got between my buoyancy compensator vest and neck and looked me in the face. They are very poisonous. In Australia everything is out to get you. I held my breath, very carefully loosened the vest, and the snake slithered out.

Let's try for another experience of a less terrifying nature.