This one about humpback whales and their songs. They all get together off the coast of Western Australia and the males start singing a song together. Fun side fact: I used to be in the Navy and sailed around these waters, and we both saw these humpbacks quite often, as well as listened to their songs through the sonar array and ‘underwater telephone’. Humpbacks in the Pacific, 5000kms away, hear this song that travels that far and start to sing it too. Just amazing stuff, and that’s what I love about documentaries, always come away feeling closer to nature and able to parrot some interesting facts.