A ship having a multi-mode hull where the draft, seakeeping, and payload-carrying capacity are varied to match the requirements of the required mission. For example, the ship has a hull with first and second hull portions and with an interconnecting hull structure, and has a ballasting system within the hull portions and operable to adjust the draft of the vessel in conjunction with the payload carried by the ship so that the ship can perform a designated mission. The hull is designed to have an adjustable hull depth according to the payload carried to perform the mission and augmented by the ballasting system so as to optimize draft, and thus hull mode, to meet mission requirements. As a result, the ship operates in four distinct modes as follows: very shallow draft (logistics mode), shallow draft (catamaran mode), moderate draft (SWATH mode), and deep draft (stealth/low-freeboard mode).