Well, according to the video I have posted above playing dead or splashing violently is not a good idea. They advise going for the eyes - well maybe it can have some effect but to me it sounds like last resort action. I wouldn´t count on it.
But other videos below how to survive attack of various animals (bear, gorilla, ...) are quite informative - check them out.
Here is trick a diver devised that goes strangely ignored. What is the one creature sharks don't mess with smaller than they are? It is the sea snake. And what does a sea snake look like? It is black and white banded. This diver painted his wetsuit with white bands and reported every shark within visual range sudenly broke off when he appeared.
Very interesting trick.