1. About two-thirds of all marine life remain unidentified.

2. No one knows what made this sound.

3. There are probably halibut bigger than this, which broke world records at 515 pounds.

4. We might not have identified eight whale and dolphin species.

5. About 90% of the ocean is still unmapped.

6. Because 95% of it we haven't explored, meaning there COULD be mermaids.

7. Mysterious rivers and lakes exist underwater, with creatures found nowhere else.

8. There are likely more new deep-sea shark species than even this fishing expedition turned up with last year.

9. How much fish would a fishery fish if a fishery could fish deep-sea marine habitats?

10. Somebody just south of New Zealand caught this 39-foot-long Colossal Squid, but we don't know a lot about it.

11. In the Triassic period, the Kraken may have eaten bus-sized Ichthyosaurs.

12. We know about seven underwater waterfalls, but there could be more.

13. It's also unclear how many valuable minerals are hiding out in the water.

14. Off the coast of Cuba, some researchers discovered a possible lost city..?

15. And no one's entirely sure what this rock structure is doing here.

16. But the biggest unknown is how to go about studying the ocean, when most of it doesn't really want to be found.
