For your amusement and entertainment, I have uploaded a short clip showing the ignition of a fire piston immediately after retrieving it from being submerged in a glass of water. I did this last summer to illustrate the harsh condition capability of the device.
http://www.imagestation.com/album/pictures.html?id=2100431105
http://www.imagestation.com/album/pictures.html?id=2100431105