Every winter, Norwegian marine biologist Andreas B. Heide sails north in search of whales, especially orcas. He’s not just there to document these incredible creatures from the boat, however — he jumps in and swims right along with them. Orcas are some of the most powerful and intelligent predators on the planet, but by approaching them with respect and establishing trust, Andreas has been able to gain perspective on how they live, interact, and even play. His hope is to increase awareness for conservation efforts by documenting his up-close-and-personal interactions with these surprisingly gentle giants. The above video by Great Big Story shows what it looks like to swim with them.