Try technical drawing film. its a kind of plastic "paper" and you can draw on it with a pencil when wet, even underwater ! (If you get to that level a prayer book may be better though
). Its sold in big sheets and I just cut it up to make smaller note pads.
It costs £2-3 per big sheet A1 size, and you can make many note pads from it. I even have a small piece stuck to my console, so i dont forget which berth they told me to tie up to etc.
When you have finished with the notes just rub them out. As long as you use a soft pencil it last ages.