Where is the thinnest point of the earths crust?

It is beneath the sea an is called a ocean crust. This is the thinnest point because the ocean water is so dense (heavy) it flattens the crust (because there's millions and millions of gallons of water...... That's heavy!!!) that's why there are oil rigs at sea because it's only around 5 kilometres thick, unlike on land it's around 50 kilometres thick!!!