NZ-Orient Line is to introduce a third vessel, the Koral, into service next month to reduce its 21-day service to 15 days. The move will improve the line's sailing frequency to twice-monthly and increase its port coverage to include Jakarta and Surabaya on a direct call basis. ''The 18,000 deadweight tonnes (dwt) Koral, which is a semi-container vessel, will complement the two existing NZOL vessels Bimantara Satu and Bimantara Dua,'' said a company spokesman. The vessels will provide direct sailings between Surabaya, Jakarta, Singapore, Bangkok and the Pacific Islands of New Caledonia and Fiji as well as Auckland, Tauranga and Napier in New Zealand. The line is to add a modern, multi-purpose 1986-built Tweendecker to its fleet. It has a capacity of 925 20 ft equivalent units (TEUs) including 45 reefer slots and can also handle unitised breakbulk cargoes up to 95 metric tonnes.