If your a looking for an external hard drive that can withstand fire, and is fully submersible in water, the check out the ioSafe Solo External Hard Drive.
The ioSafe Solo External Hard Drive is ideal if you need to protect your data from every eventuality, and is capable of surviving a fire for 30 minutes and being submerged in ten feet of water for 10 minutes.
It comes in a choice of sizes ranging from 500GB to 1.5TB, prices start at $199 for the 500GB model up to $349 for the 1.5TB model.
ioSafe via Engadget
The ioSafe is available in the UK from The Tech Bag, prices start at £230 for the 500GB model up to £345 for the 1.5TB model.