The Bluetooth connection between the right and left Dash will have breakups under water. We can roughly identify the activity with the movement sensor, and increase the buffer of the Bluetooth stream, and thereby deal with a broken connection.
The touch interface is disabled while submerged. The tapping will work while wet, while the sliding depends on how wet the surface is.
You can start and skip music, but maybe not change activity (LHS) or select playlist (RHS) or change volume (RHS).