Matt Hawkins is a marine diver.
Well, yes but when we first meet him, he is the designer of undersea robots which require his knowledge of how things work deep underwater but he does a lot of his work on dry land.
Several years prior to starting this interesting profession, Hawkins was a Navy SEAL for several years and a darn good one. Then a mission to Afghanistan went terribly wrong and some of the men under his command were killed and Hawkins was nearly one of them. Besides coming close to dying he saw one of his legs terribly mangled. When he pressed hard to find out what went wrong and why and who, the Navy fought back and gave him a psychiatric discharge and tried to forget about him.
That was then and now he makes devices that work beneath the waves. At least he did until a super hush-hush government agency with no name comes asking for his help.
Hawkins is described as having a "thick mane of salt-and-petter hair and a gray-streaked beard". "Hawkins had inherited his warm complexion, rugged profile, and lava-black eye color from his mother's Micmac Indian forebears. His big-boned physique, with its broad shoulders and six-foot-two inch height, were gifts passed down from his English-Irish ancestors."
He has a very good sense of humor and generally liked and respected by those with whom he works but is still "considered a lone wolf and eccentric", largely because he "was wrapped in his shell as tightly as a barnacle and the hard edge behind his easy quiet-spoken manner made some people nervous". For his part, Hawkins knew he was known for being unsociable because of "his inability to trust in his fellow humans. He preferred dealing with robots. If they failed him, he could replace a part."