Eventually DeBlasio became a sharpie.

In New York and New Jersey coastal fishing parlance a “sharpie” is one who fishes seven days a week all summer long, selling his fish to the market to make a living. Sharpies supposedly have fishing down to a science, to such a degree that they only go to particular places, at particular times, using particular fishing methods, and come back with a boatload of fish while everyone else wonders in amazement.