This is such a tough question, as I have encountered so many amazing creatures while diving. It's one of the reasons I am so passionate about diving. One of the most memorable encounters was when I was diving off of Moorea, which is one of the Tahitian islands. Even before the dive, we had a whale breach the surface which was an amazing experience. However, even more amazing to me was about half way through the dive when a green turtle came up from the sea floor and was almost nose to nose with me. Its shell had one of the most intricate designs you could imagine. It looked as if it was painted on the shell. I only wish I had an underwater camera at the time, because it was almost unbelievable. Although, as with most things, I can bet no picture would have done the scene justice. Visibility was perfect as well. The rest of the dive was fantastic, but the intimacy of this beautiful turtle swimming up to say hi was the highlight of the dive.