Jeez, this is one of the hardest things to draw in black and white, and you nailed it!
Thank you! I'm so glad it came out well, because water is crazy and I was ready to bang my head against something. Steve Lieber pointed out the importance of having a light source (which seems completely obvious now, but had escaped me). So on his recommendation I printed out pictures of water off the Internet after having played with the threshold in Photoshop, which helped. I also found this strangely helpful, in showing the structure of water and how it moves. In the end, it was actually a lot of fun.