The soaked notebook will take days, if not weeks to dry out. I'm still fascinated by how the pages turned out and differing ways various different inks were affected by the rain. It's also been an interesting test of the permanence of various pens / inks. In reverse or of permanence:

Waterman Florida Blue fountain pen (washable) - disappears completely.
Diamine Blue-Black fountain pen - slowly dissipates into the damp page, gradually becoming less and less legible.
Parker Permanent Black fountain pen- an orange colour leeches out leaving blue which slowly smudges and fades.
Sheaffer Black fountain pen - Also leaches orange, but stays black fading to grey.
Waterman Black roller ball. Leeches pink and blue but stays legible in places.
Pilot G2 roller ball. Smudges a bit but leaves a sharply defined line.
Pilot G-Tec. No change.
Cheap ballpoint. No change at all. Annoying, that. Cheapest nastiest pen is the most permanent...!

The pen in the pic is a Waterman Laureat.