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5 Facts About the Oceans That Show How Little We Know About Them

July 28, 2026

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Oceans cover more than 70% of Earth’s surface, yet they remain one of the least explored places on the planet. Here are 5 facts about this submerged world.

1. We’ve mapped more of the Moon and Mars than the ocean floor

According to NOAA (the US oceanic and atmospheric agency), only a relatively small portion of the seafloor has been mapped in high resolution — much of the ocean bottom remains, quite literally, uncharted territory.

2. The “twilight zone” is nearly pitch black

Below about 200 meters depth begins the mesopelagic zone, where sunlight barely reaches. This is where some of the strangest creatures ever recorded live, many of them bioluminescent.

3. The ocean produces much of the oxygen we breathe

Microscopic marine organisms like phytoplankton are responsible for a significant share of the planet’s oxygen production — by some estimates, more than all land forests combined.

4. There are mountains and canyons bigger than any on land — just underwater

The world’s longest mountain range, the Mid-Ocean Ridge, stretches over 60,000 km — far longer than any mountain range on dry land.

5. New marine species are discovered all the time

Even today, research expeditions keep finding unknown species in the deep ocean — a reminder that there’s still a lot left to discover, quite literally, underwater.


Want to explore a bit of that world?

Snorkeling Gear Set with Anti-Fog Mask — great for getting a close-up look at marine life in shallow water.

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