It is truly astonishing how little mankind knows about the ocean floor, with an estimated 5 to 7 percent of its mapped despite the fact that it covers 70 percent of the Earth’s surface — and a new $7 million competition aims to start changing that.

XPRIZE, a non-profit foundation that is focused on the fairly general category of managing public competitions to improve mankind, is launching an ocean challenge lasting three years that would focus on mapping the ocean floor, according to a National Geographic report.

The winner will get quite a payday: XPRIZE is offering a $7 million purse.

To compete, participants will need to complete a series of tasks with devices launched from either the short or air that can operate at a depth of up to 4,000 meters and can make high-resolution maps of the sea floor. The devices should be able to snap high-definition images of objects in a sort of treasure hunt. They can also grab a cool $1 million extra if they’re able to also monitor chemical and biological compounds in the water column, according to the report.

It’s all part of XPRIZE’s “Ocean Initiative,” and is the third in a series of prizes to be launched by 2020 that will attempt to tackle challenges in the ocean and in order to better understand it and preserve the things that are in it. A previous challenge involved cleaning up oil spills.

This particular competition was sponsored by Shell Oil Company and the National Oceanic and Atmospheric Administration in addition to XPRIZE.

Over the course of the three years, there will be nine months for team registration, and anyone can enter.