One of the great joys of reading is that you can do it anywhere. A relaxing bath is a prime opportunity for getting through a few chapters, but woe betide those who let their paperback slip into the tub or accidentally splash water into the most delicate part of an e-reader. And, lo! Amazon has a solution with its Kindle Oasis. The device can survive in fresh water up to a depth of two meters for as long as an hour.