"It came in front of my lens and then hung out with us," Gruber says in the video. "I wanted to let him go after a little bit. I felt like he came and he divulged his secret."
Now that marine biologists know that turtles are capable of this magic-seeming biofluorescence, the next step is to figure out why they're glowing: Is it for camouflage? Or to communicate with other turtles?
Finding the answers won't be easy, since many species of sea turtles are critically endangered.