This occurs only when the action is taking place underwater. Half of the time, when anyone does anything, bubbles will appear around them for no apparent reason. Always. This makes absolutely no sense. There are a few reasons:
- The characters are usually way below the surface, where no air should logically be.
- There is no reason that simply waving a hand around should produce bubbles on the ocean floor.
These bubbles will disappear for some reason after they have trailed a character's movements. Again, this makes no sense as they should rise all the way to the surface.
The likely reason is to remind viewers the scene is underwater.
Subverted when cavitation