David M. Lawrence has never decided what he will do when (if) he grows up. He is a scientist who teaches geography, meteorology, oceanography and (sometimes) biology at the college level. He is a journalist who covers everything from high school sports to international research in science and medicine. He is a scuba diver looking for a way to make a living on the water. When not consumed with those activities, he looks at his guitars and wonders if he’s too old to become a rock god. (It would help if he could actually play.) He lives in Mechanicsville, Va., with his wife, two children and a menagerie of creatures with legs, scales and fins.