The shakas hand symbol - a.k.a hang loose - is a common gesture in Tahiti. It essentially means no worries, take it easy, be happy, okay, see ya later... It's a diverse gesture, and that's why tahitians make the symbol frequently.
The gesture originally came from Hawaiian surfers. When those surfers came to Tahiti, the Tahitians loved it and it has been ingrained in the culture ever since, amongst males and females alike.
So if you ever get to Tahiti, in true local spirit, do the shakas!