There are some waves that you really don’t ever want to encounter when you’re swimming in the ocean. Square waves look like a giant chess board over the ocean. It's pretty awesome but incredibly dangerous.

When you look at the seas and oceans on the map you might think that they just flow into each other. It seems like there’s only one big ocean, and people just gave different names to its parts. Well, you’ll be amazed at how vivid the borders between them...