Lying in my bunk, I hear an occasional clicking from the hull below me. No, it isn’t krill dining on algae, although the sound is similar. It can’t be krill, because I no longer have algae growing on my hull. What I’m hearing is the boat’s Ultrasonic Marine anti-fouling gear, and it tells me that any nasty growth emerging on the boat’s bottom, including algae, is being destroyed before it becomes attached. Sorry, krill.