Unusual Paperweight

This unusual paperweight is a perspex cube that contains two liquids that do not mix. At the bottom is a dark blue liquid, and above is a clear liquid. Not sure what the liquids are, but at a guess the clear liquid is some form of oil, and the bottom layer is water based, with a blue dye. Either way, the blue liquid is denser that the clear liquid.

Inside the paperweight are two sporting characters, one on a sailboard, and the other a balloonist.

The sailboard is of a density such that it sinks in the clear liquid, but floats on the blue liquid. A tiny white float at the top of the sail keeps the whole sailboard upright.

The balloon is lighter, and floats to the top of the clear liquid. Again there is a tiny little white float at the top of the balloon, which keeps it the right way up.

Overall, the sailboard skims the blue ocean below, and the balloonist floats up in the air.

A clever design, with a little bit of physics going on in the background!