And yeah, good luck with that waterproof laptop.
I don't think he was looking for a water tight casing, just something that you can use on a planet that is 70% water and sometimes has moisture in the air in the form of humidity, mist or rain. There is a difference between getting caught outside in the rain with a notebook computer that is not under water tight protection and dropping it in a pool, spilling something on it, or leaving it on an outdoor table (and letting it rain on it)