Eh eh eh,Ricardo,you are the "real problem solver"...
I think that compass+pencil(your choice) is the best solution!
Someone uses compass+wetnotes(using the hardcover as a table) leaving the pencil "free"....
We have used the "wetnotes refill" for printing the sheets,but if Ricardo gives you the .pdf with the A4 format,the best choice is to use waterproof laser printable paper (Duracopy,etc...).
Ciao,Davide