“Pop star Katy Perry recently made headlines by joining a historic spaceflight aboard Blue Origin’s New Shepard rocket,” announced the TV anchor.
“Hey, what’s that about?” I asked, curiously. “Why are celebrities going to space?”
“Not just celebrities,” my brother replied. “They got the spotlight for sure but it was actually the first all-women crewed flight.”
“Wow,” I said, impressed. “So this is maybe more than just space exploration.”
I paused, thoughtful. “What about exploring the world underwater? There’s an entire mysterious universe down there too.”

And the thought lingered. We pour time, money, technology and even human lives into unlocking the mysteries of space. But what about Earth? What about the ocean that covers more than 70% of our planet? Some say only 5% has been explored but is that even true? How much do we really know? In this article, we dive deep into those questions, layer by layer, backed by data and discoveries.

The Numbers That Speak Volumes
The ocean spans an incredible 71% of Earth’s surface, roughly 360 million square kilometers. Its average depth is about 3,682 meters. Yet, nearly 80% of this vast underwater world remains unmapped.
As of June 2024, 26.1% of the global seafloor has been mapped using high-resolution multibeam sonar technology. These sonar systems, mounted on ships, send out sound waves to reveal the contours of the ocean floor.
Still, mapping the seafloor is one thing, understanding the life that thrives is another. Scientists estimate 700,000 to 1 million marine species may exist. Shockingly, two-thirds are still waiting to be discovered. About 2,000 new species are confirmed each year.
So, while we can measure how much of the seafloor has been mapped and how many species we’ve named, we still can’t say exactly how much of the ocean, its waters, depths, and life has truly been explored.

Why is diving into the unknown depths difficult?
Scuba diving lets us peek beneath the surface, but only so far. As divers descend, they face crushing pressure, disorientation, and serious health risks. Most recreational divers stay above 40 meters.
To go deeper, into the domain of technical diving, one needs expert training, specialized gear, and detailed planning. Every extra meter becomes a battle against the ocean itself.
And depth isn’t the only problem, remoteness is a major barrier too. Many ocean regions are simply too far, too isolated, or too dangerous to reach easily. Strong underwater currents, poor visibility, and extreme weather add to the complexity.

Tools That Changed the Game
Echo Sounders were first used in the 1920s. They send sound pulses to the seafloor and measure the time it takes for the echo to bounce back, longer times mean deeper waters. But it is not as simple as it sounds.Ocean conditions like temperature, salinity, and sea life affect the readings.
To improve accuracy, scientists developed multibeam echo sounders, which send out hundreds of beams at once for a more detailed map.
Then came ROVs-Remotely Operated Vehicles. These underwater robots are guided by humans on surface vessels, like playing a video game. Equipped with lights, cameras, arms, and sensors, ROVs can capture samples, record videos, and collect data, all without a person ever entering the water.

Where Do We Stand Now?
The Seabed 2030 Project, a collaboration between the Nippon Foundation and GEBCO, aims to map the entire ocean floor by 2030 and make the data open to everyone.
And just recently, on March 10, 2025, a press release announced:
The Nippon Foundation Nekton Ocean Census discovered 866 new marine species found at depths between 1 to 4,990 meters.
This tells us one thing, the deeper we dive, the more we discover. And we’ve barely scratched the surface.

Is it possible to explore 100% of the oceans?
Well, the National Oceanic and atmospheric administration bluntly says NO, “We continue to discover new features and creatures, clues to our past, and resources that can improve our future. But the ocean will never be fully explored. Earth is constantly changing, and it’s important to understand these changes given the importance of the ocean in our everyday lives”.

Why does it matter to us?
No matter where you live, by the coast or far inland, the ocean quietly shapes your everyday life. It helps produce the air we breathe, influences the weather we experience, and plays a part in the journey of almost everything we buy and eat.
Most of what we know about the ocean comes from its shallower regions. But it’s the deep sea that’s becoming more important than ever. Deep waters support major fisheries, drive livelihoods, and hide reserves of oil, gas, rare metals, and minerals.
And that’s not all, these depths may hold answers to diseases we’ve yet to cure, and ingredients for the next generation of medicines, enzymes, or even skincare.

Ocean’s whisper
While we chase the stars, Earth’s greatest mystery lies beneath the waves, only a fraction of our vast oceans have been explored, yet they hold keys to our past, present, and future. But with plastic pollution and human impact on the rise, the question isn’t just how much more can we discover? It’s- How much can we still protect?
Written by: Tanvi Mongia
Edited by: Dr.Reshma Patil