how deep is the ocean?

i have a fear of the ocean .. I always think about the water going away and drying up and alll we see is a big giant hole 😩😩😩😩😩😩 and we seee all the sea animals in. that giant hole under us. it gets me anxiety just by thinking of it 🤦🏻‍♀️ you know how many treassure and a lot of things we can find if the ocean water isn’t there anymore? omg .