I am seeing this post go around facebook with 33k likes and 62k shares:
”The famous Italian diver Enzo Mallorca (sic) dove into the sea of Syracuse and was talking to his daughter Rossana who was aboard the boat. Ready to go in, he felt something slightly hit his back. He turned and saw a dolphin. Then he realized that the dolphin did not want to play but to express something. The animal dove and Enzo followed.
At a depth of about 12 meters, trapped in an abandoned net, there was another dolphin. Enzo quickly asked his daughter to grab the diving knives. Soon, the two of them managed to free the dolphin, which, at the end of the ordeal, emerged, issued an "almost human cry" (describes Enzo). (A dolphin can stay under water for up to 10 minutes, then it drowns.)
The released dolphin was helped to the surface by Enzo, Rosana and the other dolphin. That’s when the surprise came: she was pregnant!
The male circled them, and then stopped in front of Enzo, touched his cheek (like a kiss), in a gesture of gratitude and then they both swam off.
Enzo Mallorca ended his speech by saying: “Until man learns to respect and speak to the animal world, he can never know his true role on Earth." ~ Vangelis.”
Overall I don't think that a diver encountering a dolphin entangled in a net is unlikely, but I think there are a lot of embellishments in this facebook story compared to what probably happened in real life.