In 1768, Romans became principal deputy surveyor for the Southern District (the British Colonies of , North Carolina, South Carolina, Georgia, East Florida, and West Florida). Starting in 1769, Romans surveyed the coastal waters of East Florida. Later that year, his boat sank in the Manatee River near Tampa Bay. Romans walked overland from there to St. Augustine. Well aware of the historical significance of where he walked, he later wrote that he had been "on Ferdinando Soto's tract". He outfitted another boat, at his own expense, and resumed surveying the coast in September 1770. He reached Pensacola, Florida in August 1771, having recorded depth soundings, good harbors, and sources of fresh water, and drafted coastal charts, for much of the East Florida coast.