Fastmarc said:
Those growths are fibropapilloma tumours. They afflict marine turtles of all species, but particularly greens. The disease is found throughout the world, but in higher concentrations in certain areas, Hawaii being one of them. Florida, Australia, and the Bahamas are other examples of locations that have populations with a high incidence of tumours.
My wife and I have been documenting these tumours in Hawaiian turtles since 1989. You can learn more by visiting:
I should point out that the latest research into fibropapilloma tumours indicates that although individual turtles still die from the effects of the disease, the Hawaiian population as a whole is not in danger of extinction as was once feared.
As far as I can see in these pictures, this particular honu's eyes are largely free of tumours. That indicates that the disease is regressing and the turtle will probably recover. See:
As someone points out elsewhere in this thread, the turtles are everywhere in Hawaii now. There is no better place in the world to dive if you want to see these wonderful animals.
I wanted to leave you with a nice turtle picture. We have literally thousands of pictures of the honu, but ironically the selection I have at hand is severely limited. This one, taken in 1995, is a turtle we knew as Aikane. Hope you like it.