Scaffolding surrounds the USS Constitution as restoration continues, Wednesday, April 5, 2017, at the Charlestown Navy Yard in Boston. The ship enters dry dock for below-the-waterline repairs every 20 years. The world's oldest commissioned warship afloat is scheduled to return to the waters in late July. (AP Photo/Elise Amendola)
Scaffolding surrounds the USS Constitution as restoration continues, Wednesday, April 5, 2017, at the Charlestown Navy Yard in Boston. The ship enters dry dock for below-the-waterline repairs every 20 years. The world's oldest commissioned warship afloat is scheduled to return to the waters in late July. (AP Photo/Elise Amendola) Credit: Elise Amendola