I have a friend who goes to Texas A&M and tried out underwater archaeology training. He started out with rescue diver certification, you'll see why that's desirable in a second. Their scientific dive certification course consisted of traveling to Louisiana and simulating an archaeological "dig" on a sunken houseboat in a bayou. They had to dive in 0 visibility with strong cross-currents. They couldn't touch the boat, and they had to keep themselves and their fellow divers alive while doing their archaeology. Day after day after day. You have to be a physically strong individual who can recognize your limits and keep track of a lot of critical things at once.