Pens?

I'm mostly certain that a pencil won't write on waterproof paper. That's likely the main reasoning behind it.

I agree with Chris. I always carry a fisher space pen and a Rite in Rain waterproof pad. I like the way it turns into an almost full-sized pen when you put the cap on. I made a video of my setup:

http://www.geartalkwithjasonklass.com/2009/04/taking-notes-and-other-things.html

"I'm mostly certain that a pencil won't write on waterproof paper. That's likely the main reasoning behind it."

A #2 pencil works just fine on Rite-in-the-Rain paper.
I know. I just tried it. It takes a fair bit of rubbing to get it to smear, even when wet.

And their home page shows a note pad and pencil together.

But I like an Ultra Fine Sharpie for its fine point and "for sure" won't smear ink.

A #2 pencil works just fine on Rite-in-the-Rain paper.
I know. I just tried it.

What about waterproof map paper? A lot of people don't carry pads and just write in the margins of their maps.

"What about waterproof map paper?"

Well, I just wrote some notes on a Trails Illustrated map with a #2 pencil. Its not as permanent as RitR paper but it would survive.

Not all WP map paper is the same. There are at least two different technologies. I don't know which one NG/TI uses.

>> What about waterproof map paper? A lot of people don't carry pads and just write in the margins of their maps.

I don't habitually carry a notebook hiking, but I carry a notebook of waterproof paper on deployments and I know that my old No. 2 works on it just fine.

Personally, for hiking I usually just carry maps on regular paper, in a Ziploc. (I've usually printed them myself.)

I just took a look at a Trails Illustrated map, though, and I guess I can see how one might doubt that a pencil would work well on that shiny waterproof stock. I gave it a shot in the white margin, and the pencil did write on it, though the marks were thin rather than a nice satisfying wide dark line. It didn't smudge, though, and was certainly legible. However, it was very difficult to read these light marks on the map itself, what with the colored ink background and contour lines and whatnot.

So, I guess I'll buy that argument for waterproof maps.