Getting the materials for the bridge will be a bit tricky. Where can they--

--THREE! SPLASH. Ah. Never mind. She has an idea.

"Some of the students nearby have clean toothpicks and other things with them," she points out as she begins to draw the outline of the moat around the castle. They were preoccupied with the current game of tossing people into the water, it seems. "I can get some of that from their blankets."

After asking politely of course.