THOMASTON — With a tumultuous thunderstorm looming down from the northeast, it was quick, yet celebratory, business easing Ladona into the St. George River July 24. She went in like a charm, and the soft launch of the former Nathaniel Bowditch was marked by champagne, and many admiring glances of this one-time yacht, whose sheerline had been smoothed back to her original shape at Lyman-Morse boatyard, in Thomaston.