It was entangled in fishing line and had a hook embedded in its pectoral fin. It was so entangled in fishing line that it couldn’t move or swim properly. (I say “it” because I have no idea whether this dolphin was male or female.) It was in trouble and needed help.
If this is real — and it looks real to me — a wild dolphin in trouble seems to actually ask a human diver for help. Thankfully, this particular diver was both able and willing to provide that help.
The dolphin seems to know humans are potentially dangerous, but also that we might be able to help it. It ignores the manta rays, which have neither the intelligence to know it is in trouble nor (probably) the compassion to care. It seems to come in slowly toward the man. Cautiously. But it has little choice, because it will probably die without help.
It first swims slowly past the diver, twisting and turning as if to show the man its predicament. Then it comes back and stays as long as possible while the man works to remove the entangling fishing line — until it has to return to the surface for air.
Even then, it returns for more help and lets the diver poke and prod its body as he removes more fishing line and frees its range of motion. But eventually the dolphin swims away with the hook still in its flesh.
Why did it swim away before the rescue was complete? I have no idea. Maybe removing the fish-hook hurt too much. Maybe it could no longer control its fear of the icky humans. Figuring out why humans do what we do is difficult enough; reading the mind of a cetacean is even riskier.
Regardless, it seems to me this is one more in a long line of incidents showing how intelligent and sentient some non-human animals are.