Eli5: Why is wet sand sticky above water, but when submerged it acts like dry sand?

Question

Eli5: Why is wet sand sticky above water, but when submerged it acts like dry sand?

In: Physics

Answer 1

When sand is above water, the moisture on its surface creates a sort of “glue” that makes it sticky. However, when submerged underwater, the water fills the spaces between the sand particles, reducing friction and making it act more like dry sand. So, the water changes how the sand behaves by filling in the gaps between the grains.