Make a waterproof slate that you can write on with a pencil - even if it is wet
Plastic container - such as ice cream container or butter tub
240 grit sandpaper
Cut up the containers into suitable notepad size eg size of 6 inch smartphone.
Lightly sand each piece of plastic so it is no longer smooth.
You can now write on your plastic note slate. You can write on it when it is wet (I have heard you can also write on these when submerged in water).
Use this in you emergency kit or first aid kit instead of paper.