He knew that experienced divers moved with #minimal effort, allowing them to burn their air more slowly and extend their dives. But on his first trip down he quickly learned that theory and reality were very different things.

As he added more air to his BCD, trying to arrest his descent, he looked over to see an enormous sea turtle gliding past. Astonished, he watched in wonder, his heart rate and breathing slowing as the world paused around him.

(https://b-ark.ca/c8uYya)