Good luck getting it
In search of gold? Looking for the next gold rush? The oceans are a good place to look, however, it's not as easy as panning for gold.
Ocean waters around the world contain about 20 million tons of gold in them. When I say "in" that is meant literally, there is gold in ocean water. Unfortunately, the concentration lies on the order of parts per trillion, making it extremely difficult to get.
Based on today's spot price of gold at $42.51 USD per gram, that amount of gold would be worth roughly $771 trillion. Compare that with the United States gross domestic product (GDP) in 2016 of 18.57 trillion and its 41 times. Alternatively, you can compare it to the world domestic product of $78.28 trillion in 2014, almost 10 times the entire world's domestic product.