It's so big that even with all the cutting-edge technology available to modern science, 95% of the ocean still remains completely unexplored.
To help shrink that knowledge gap, the nonprofit Xprize - known for awarding millions in prize money in public contests - announced its latest competition: to explore the ocean at previously uninhabited depths.
Jyotika Virmani, senior director at Xprize, says the contest was designed with a raft of different breakthroughs in mind.
These range from archaeological findings, including shipwrecks, to the discovery of novel disease cures in ocean life, to the many unknown benefits human can't even imagine right now.
"One of the main goals is to bring the deep sea to the public," Virmani says.
As per the usual Xprize conditions, the competition is open to everyone who submits an idea. Registration will last until September of next year, Virmani says, at which point Xprize will start winnowing down the contestants over the course of three years based on several criteria.
Of the $7 million in total prize money, $4 million will go to the team that produces the highest-quality image of the ocean floor, while $1 million will go to the second-place team. Another $1 million will be divided among up to 10 teams that advanced to the second round, and the final $1 million will go to the team that best detects the source of a biological or chemical signal, like an oil spill.
The teams' devices must also be able to do all this at more than 13,000 feet below the water's surface, where pressures reach 5,800 pounds per square inch.
And unlike the multi-million-dollar vessels normally used to explore the ocean, the Xprize devices will be deployed from the shore or by air.
Virmani says the constraint follows in the footsteps of past Xprizes, which routinely demand their participants to create a solution that can be produced on a wide-scale and be accessible to millions.
"Without understanding the environment, it's very hard to value it," Virmani says. "And without valuing it, people will not care and respect it."