The 10-day drill brought together four submarines, four rescue ships and three deep submergence rescue vehicles from South Korea, the United States, Japan, Australia and Singapore, the defense ministry said.
China, France and six other nations have sent military officials to observe the biennial exercise, which was first held in 2000 to improve capacity to salvage wrecked submarines, the ministry said.
The United States sent a 6,900-tonne submarine and a 1,200-tonne South Korean submarine also took part in the exercise, previously hosted by Singapore and Japan.
South Korea has nine 1,200-tonne submarines and plans to deploy three 1,800-tonne vessels from 2007.
Under a military alliance with the United States, American nuclear-powered submarines patrol the Korean peninsula. The communist North has more than 90 submarines.