Re: Waterproof eyebrow pencils?[ Edited ]
Make Up For Ever makes a really cool gel product for brows that is waterproof, sweatproof, and rub proof! I think it's just called Aqua Brow. The color selection is limited (especially at Sephora) but if you're a brunette you'll be all set!
EDIT: Tarte also makes a waterproof brow mousse called Tarte Amazonian Clay Waterproof Brow Mousse, and Stila's Stay All Day Brow pen is waterproof as well. Additionally, there's a Sephora brand retractable brow pencil that is listed as waterproof.