The assorted ropes, sails, masts and other rigging of the ships spread above the decks below in a well-oganized yet confusing tangle. The Half Moon, as a sengokobune, is a three masted,square-rigged affair. At center deck is the great mainmast, rising seventy feet above the deck, atop which is the crow's nest and which provides much of the ship's thrust in a good wind. At the bow is the fifty foot foremast, secondary propulsion and provider of speed. At stern is the smallest mizzenmast, standing only twentyfive feet high. Each mast supports several square sails apiece, each bearing nine ropes to keep it in place, tacked and taughtened to catch every possible breeze.
For full maneuvarability, at least three must attend the ropes of each sail.