We had a brand spanking new Makita Lion 18v that got properly submerged in a leaky 'dry' bag during a hours worth of wading on its first ever trip.
The drill was OK (and still is a good few years later) after I'd dropped the gear box apart to empty the water!! Plus I left it in an airing cupboard wrapped in silica gel sachets.
Two of the batteries survived after the same treatment as above. This was principally because the circuit boards withing the batteries seemed to be coated with a water proof sealant layer.
The third battery however was completely fried with the chips etc on the circuit board actually burnt.
I guess it depends on the complexity of the electronics within your drill. I wouldn't expect switch gear etc to last very long at all as they'll soon rust/corrode. Cells withing the batteries would be similar I suppose. I recall some old bosch NiCad cells being wrapped in paper.