How might one write underwater?

[Dwiesel McAllister]

In my WIP, I have an aquatic race, the Ondai. They're fairly civilised, which means they'd have to have some kind of way of quickly writing down information and easily disseminating it, and I don't think stone tablets are going to cut it.

I have no idea what is involved here. I've heard of "underwater" pens (though I don't know what they do), but paper and papyrus would just melt. Would parchment or vellum be a better option? And how would they get the ink to stay on an already saturated item?

A "magic" solution isn't really acceptable here. The Ondai's abilities don't lie in that particular field. It would have to be actual working tech (though not too advanced), either developed by themselves or adapted from another race. There is also the possibility that they were given the tech by another race as a gift, but if the pens, ink, paper, etc. were in fact "magic," they would be permanently reliant on the other race for communication, so not a good option.

Thanks in advance for your help! I'm asking here first before I dive into the internet.

[MichaelB]

Undersea divers needing to communicate with each other use chalkboards. At least, the men on 20000 Leagues Under The Sea did.

http://upload.wikimedia.org/wikipedia/commons/e/e8/Schiefertafelmitschwamm.jpg
A 1950s dive slate. Could be written on using chalk, compressed clay or soapstone. By nature, though, it's temporary. If you want permanent writing,. consider clay tablets (http://en.wikipedia.org/wiki/Clay_tablet). I don';t know how clay tablets would hold up underwater, though, but probably a lot better than paper or parchment.

On that note, parchment is made of compressed sheets of flax. Why can't your people develop an underwater parchment by compressing seaweed sheets, or other waterproof plant?

[ZeissIkon]

Modern divers use grease pencils on a sheet of acrylic. It doesn't wipe off accidentally as easily as chalk on a slate under water (which almost just washes off from currents), but still wipes up neatly with a cellulose sponge or cloth.

Modern ball points will write under water, if you have a suitable medium; the ink is oil based, so doesn't mix with water, and a primitive version of this could be made from animal fat (especially if there's a heat source to render the fat -- deep sea geothermal vents?) and carbon particles (sea coal, ground fine), though it might be tricky to deliver the oil-based ink controllably under water. Writing on vellum (animal skin, which would be very soft in water) might work. Writing with a waxier "ink", more like a crayon or grease pencil, on something like polished slabs of coral, the nacreous interiors of large shells, or similar might be more believable -- but not very permanent. For permanence, they might use knapped stone tools (knapping works better under water than on the surface -- fewer wounds from flying stone chips, and less chance of shattering the tool late in the game) to carve in something semi-hard (like coral, shell, etc.).