A side-on sea drawn entirely in text: a travelling swell plus a live wave-equation surface. The pointer is a solid body — where it cuts the surface it shoves the water into a bow wave, and the faster it moves the more of it bursts off as droplets that arc under gravity and fall back as ripples, foam and bubbles, with the water volume conserved. Plunge in from above for a crown splash, press to blow a crater. Left alone, a skipping stone skims across now and then.