For thousands of years, humans have traveled on the surface of the water, and at the same time have wondered if it was possible to travel under the water like a fish.

The idea of underwater travel stuck around for centuries, but eventually humans did figure out how to travel

under water even if the first efforts were not successful. Learn more about

submarines, how they were invented and how they work on this episode of

everything everywhere daily. and how they work on this episode of Everything Everywhere Daily. Book your ticket to happiness with Sun Express Airlines. The The idea of traveling underwater goes back a long way. All it took was to look at a fish swimming to wonder what it would be like to be that fish.

When humans began using ships to engage in warfare, it didn't require much imagination to realize

that if you could sneak up in your enemy below the surface of the water, you could wreak havoc on them.

There are images of ancient Egyptians who use propyrus reeds to breathe underwater to sneak up on prey while hunting.

Likewise, Alexander the Great supposedly used an early diving bell during the

siege of Tyre which is in modern day Lebanon. These of course weren't really submersible vehicles,

but they did show the desire to be able to travel and explore underwater.

The problem of underwater transportation was actually much bigger than the

agents realized.

First, you need a body for your vehicle that'll be watertight.

Ancient ships are made out of wood, which

would often have slow leaks. The state of metallurgy at the time wouldn't have allowed for

water-tight seams between metal sheets to make up a hull. This is especially true

when you consider the great pressures that

submarines must face when they're underwater. For every 10 meters you descend below

the surface, water pressure increases by one atmosphere. Holding back pressurized water is much more challenging than just

trying to be watertight at the surface. Then you need to be able to control your

buoyancy. It's easy to build a ship that floats and it would also be easy to build a ship that would sink to the bottom of the sea.

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