Science
Ocean & Marine Science Quiz
Tides, trenches, and marine ecosystems — explore the science of our oceans.
Tides, trenches, and marine ecosystems — explore the science of our oceans.
The ocean covers more than 70% of Earth's surface yet over 80% of it remains unmapped and unexplored. This quiz dives into ocean zones, marine ecosystems, deep-sea trenches, tides, currents, and the remarkable history of ocean exploration.
Each round presents 10 randomized questions from a pool of 50, with four multiple-choice options and instant feedback after every answer. Your final score comes with a performance tier and shareable results.
You'll explore the sunlight, twilight, and abyssal zones of the ocean, discover how tides and currents shape our planet's climate, and learn about coral reefs, hydrothermal vents, and bioluminescent creatures. Did you know the Mariana Trench reaches nearly 36,000 feet deep — deeper than Mount Everest is tall?
The average depth of the ocean is about 12,100 feet (3,688 meters). The deepest point is the Challenger Deep in the Mariana Trench, which reaches approximately 35,876 feet (10,935 meters) below the surface — nearly 7 miles down. If Mount Everest were placed in the Mariana Trench, its peak would still be more than a mile underwater.
Tides are caused primarily by the gravitational pull of the Moon on Earth's water, with a smaller contribution from the Sun. As the Moon orbits Earth, its gravity creates a bulge of water on the side facing it and another on the opposite side, resulting in two high tides and two low tides roughly every 24 hours and 50 minutes.
More than 80% of the ocean remains unmapped, unobserved, and unexplored according to NOAA. We have better maps of the surface of Mars and the Moon than we do of the ocean floor. Modern technologies like autonomous underwater vehicles and multibeam sonar are gradually helping to close this gap.
Last updated: March 2026