Sharks 3D is a Mac utility that displays an underwater animation on your desktop. This program fills your screen with swimming sharks and other types of fish and plays fitting sound effects and background music.
The tool lives on your Menu bar from where you can switch between view modes (Wallpaper, Screensaver or Observation), alter animation settings, and hide the animated wallpaper from your desktop.
A surprising aspect is that, even though it displays high-quality animations on your desktop, the program is using a reasonable amount of CPU resources and doesn't slow down the performance of other running tools. Furthermore, its Observation mode is quite impressive. It's like you would sit in an underwater tank and watch the sharks swimming around you.
The only bad thing is that not all of the content is available for free. To be more exact, you would need to make an in-app purchase to be able to switch between scenes and shark species. Still, the acquiring price is reasonable and definitely worth it if you like the program's animations.
In conclusion, you should give this tool a try if you're looking for an interesting way to customize the appearance of your desktop.