Hello,

I would say they are water resistent but not completely water proof. They have a protective cover that swings over the drive portion which is inserted into the computer.

They can be splashed or dropped onto a web surface without a problem and are quite durable.

I have had reports where they were completely submerged and still worked after being left to dry.  One tip that is used frequently when a cell phone is submerged in water by accident is to put it into a bowl of dried rice overnight which will absorb all the water.