NCL ordered two sisters to join their original twins; Southward entered service in 1971. Following the nationalization of the Italian builders prices increased, and NCL canceled the second order. (The second, unfinished hull was sold to P&O debuting as Spirit of London in 1974. In 1978 she was transferred to the Princess division of P&O and sailed for 14 years as Sun Princess).
Southward was sold in 1994, and currently sails as Perla for Louis Hellenic.