Roman Mars

It's also historically one of the deadliest places in the UK to travel by sea.

If you're into shipwrecks, it's really hard not to find one here.

At least 900 shipwrecks litter the coasts of Sili, probably more.

Sometimes ships will sink on top of other older shipwrecks, so it's difficult to say for sure.

The wrecks happened on October 22nd, 1707.

It was quite literally a dark and stormy night, and there was a fleet of British naval ships bravely led by an admiral named Cloudsley Shovel.

The HMS Association crashed into one of the many jagged rocks just beneath the surface of the water.

The death toll was somewhere between 1,400 and 2,000.

It was, at the time, the deadliest shipwreck in British history.

The reason this fleet was so dangerously off course was because they didn't know their longitude, their east-west coordinates.

It was a problem that had plagued navigators and scientists for centuries.

The greatest minds of Europe, Isaac Newton, Galileo Galilei, and the Halley's Comet guy, they all tried and failed to find a way to calculate longitude at sea.

Most people thought it simply wasn't possible.

What follows is a tale of imperial greed, a lucrative contest, and an obsessive underdog who became his own worst enemy.

Maybe let's give it a try without any citrus fruits.

This grid is what gives us GPS coordinates.

For example, the Pandora building in beautiful uptown Oakland, California, that's around 37.810 north, 122.267 west.

Which was annoying.

Before the age of GPS, the best navigational tool available was the sky.

The sun, the moon, and other celestial bodies were your reference points, no matter where you were in the world.