They cover nearly 70 per cent of our planet's surface.

But Earth's oceans are largely unexplored, with 95 per cent of our waters still a mystery.

Now, scientists have ventured to the Nazca Ridge, where they have uncovered a huge underwater mountain teeming with life.

The seamount is over 1.9 miles tall - one-third as tall as Mount Everest - and is home to at least 20 never-before-seen species.

Incredible footage provides the first ever glimpse at these creatures, including a sea toad, flying spaghetti monsters, and a Casper octopus.

The new seamount was discovered by a team of oceanographers from Schmidt Ocean Institute as they explored the Nazca Ridge – an underwater mountain chain 900 miles off the coast of Chile.

Using underwater robots, the team was able to map the huge mountain, and film some of the life thriving there.

A pristine coral garden was uncovered measuring around 800 square metres – about the same size as three tennis courts.

These deep-sea corals were found to provide shelter to an array of unusual organisms, including rockfish, brittle stars, and king crabs.

The team also captured the first ever camera footage of a live Promachoteuthis squid.

This genus is so rare that only three species have been described based on only a few collected specimens, several of which are from the late 1800s.

Other unusual creatures filmed by the robot include a Casper octopus, and two 'flying spaghetti monsters'.

This expedition was the third this year conducted in the region, with the previous two expeditions documenting over 150 new species.

'Upon concluding our third expedition to the region, we've explored around 25 seamounts on the Nazca and Salas y Gómez Ridges,' said Tomer Ketter, Co-Chief Scientist and Schmidt Ocean Institute Marine Technician.

'Our findings highlight the remarkable diversity of these ecosystems, while simultaneously revealing the gaps in our understanding of how the seamount ecosystems are interconnected.

'We hope the data gathered from these expeditions will help inform future policies, safeguarding these pristine environments for future generations.'

Prior to Schmidt Ocean Institute's expeditions, this portion of the Pacific Ocean was known to be home to 1,019 species.

Now, that number exceeds 1,300 – and is growing.

'The seamounts of the Southeastern Pacific host remarkable biological diversity, with species found nowhere else to date,' said Professor Alex David Rogers, Science Director of Ocean Census.

'The work our taxonomists have conducted aboard Falkor (too), supported by Schmidt Ocean Institute team, will significantly enhance our understanding of the distribution of remarkable life forms on these underwater mountains, including several that have never before been mapped or seen by human eyes.'

The researchers hope the findings will help to piece together some of the mysteries hiding in our unexplored oceans.

'The discovery of a new seamount almost 2 miles tall – almost four times as tall as the Burj Khalifa – with a vibrant ecosystem was very exciting,' said Dr Jyotika Virmani, Co-Chief Scientist and Schmidt Ocean Institute Executive Director. 

'Only 26% of the seafloor has been mapped to this high resolution and each expedition on Falkor (too) brings into focus a little more of the unknown seabed and life on our home planet.'