Ukrainian start-up Nuka has invented a notepad that you can use underwater and a pencil that you'll never need to sharpen or replace.

Cast your mind back to the last time you wrote anything down with a pen or a pencil. Unless you're a student or a writer, it has probably been a while. Nowadays we don't write letters or jot down notes. Well, we do, but we do it all on our smartphones and computers. That might all be about to change.

Why would we continually buy paper, pens, and pencils when we have everything we need to write messages and take notes in our pockets? Well, we might be about to enter a time when notebooks and pencils don't constantly need to be replaced. That's because Ukrainian start-up Nuka has created a notepad that is basically indestructible as well as a pencil that never runs out.

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BBC caught up with Nuka at CES in Las Vegas and took the innovative new stationary for a spin. After using the pencil to write in the book, they then took it for a swim. Not only did the notepad remain intact and undamaged, but the writing in it from before wasn't even smudged. That's because the pencil you can get along with it uses neither lead nor ink.

The pencil marks the pad via a chemical reaction instead. That doesn't mean you can't use a regular pen with it, though. In fact, if you use the special solution that Nuka has also developed, you can erase ink from the notebook. The one thing you can't currently do is erase anything written using the special eternal pencil. However, Nuka is working on changing that and will hopefully have conquered that hill relatively soon.

The innovative new inventions are coming thick and fast out of this year's CES. Whether Nuka's will revolutionize the way in which we write and even communicate remains to be seen. Things like music and fashion go through trends and become popular again after years away, perhaps this new notebook and pencil will do the same for the world of writing.

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