I am a 225-pound largemouth bass, guarding a bed on the edge of Lake Jennings. Looking up through 10 feet of slightly hazy water, I see the silhouette of a boat. From its deck, John Kerr, one of the premier big-bass chasers in America, pitches a white jig and lets it settle on the lake bottom 3 feet in front of me. He gives it an annoying twitch. I watch the bait shake and shimmy for another 20 seconds. Finally, a small male bass finning nearby cannot stand the provocation anymore; he angles over and crushes the bait. "He couldn't help himself," I say after resurfacing and pulling the mask onto my forehead. "If you'd wiggled that thing any longer, I'd have bit it myself." Kerr smiles and releases the fish he just caught. In yet another "be the fish" scuba experiment (see fieldandstream.com/troutresearch), we prowled the bottom of one of the classic trophy bass lakes near San Diego. Our goal was to watch largemouth bass in spawn and postspawn modes to pinpoint some practical lessons for better fishing. Here's what we learned.