The only threatening thing you will see in the water will be of the two legged variety. The snorkeling is very good in Polynesia - fish, coral formations are great - even better than the Caribbean if that is your pleasure.

But you will need those water shoes - on land and in the water - to frolic and splash. Have a great time and don't be put off by the necessity of wearing the water shoes. Volcanoes, which created the reef system and beaches with volcanic rock, are the reason why Polynesia is so beautiful in the photographs and in person.