We love a waterproofed Kindle, and we put one through hell, but that's an aftermarket mod, not a feature that comes standard. If you want waterproofed reading on the cheap(er), the new Kobo Aura H2O is for you.
Offering IP67 certification (waterproof for up to 30 minutes if the port cover is closed) and a 265 DPI e-ink display that's tied with the more awkward Kobo Aura HD for highest in the world, the Kobo Aura H2O is great for a beach- or tub-reader who can remember to keep the flap closed. And starting at £140, it's a damn sight cheaper than a waterproof-modded Kindle. You can pick one up on Kobo's website starting October 1st.