Up to 546 workers, some with seniority of at least 20 years, will lose their jobs when the layoffs take effect this summer.
The reduction will bring the shipyard - the state's largest industrial employer - to its lowest ebb in two decades.
Pearl Harbor's labor force climbed in the 1970s, reaching a peak of 7,133 in 1983. Then began a steady decline.
In February, the Navy announced a reduction of more than 13 percent the shipyard's workforce, then totaling 4,132 civilian workers.
The cuts, which not only affected Pearl Harbor but 140 other naval facilities, were part of an effort to eliminate 15,000 military jobs nationwide.
Annette Martin, Pearl Harbor spokeswoman, yesterday said the Oahu military facility has never had a reduction of this magnitude.
"The reduction in the labor force is due to overall reduction in ship repair and modernization work," Martin said.
Earlier this year, the Navy estimated that the workload would drop by 17 percent by the end of the year. The action could cost the state'e economy $30 million a year.
Initially, the Navy wanted to cut 1,300 jobs at the shipyard, but the blow was softened by several developments:
- More than 154 workers opted to take advantage of an early retirement program that offered cash incentives of up to $25,000.
- Some 504 positions once held by uniformed sailors were converted to civilian positions at the Navy's Intermediate Maintenance Facility. As of April 11, some 400 shipyard employees have been at the facility.
With the transfer of the 400 shipyard workers, the labor force at Pearl Harbor will drop to just over 3,100 after the August cutback.
In anticipation of the August layoffs, Sen. Daniel Inouye and other members of Hawaii's congressional delegation spoke to shipyard workers in late February. They said that despite Hawaii's strategic location, layoffs are inevitable because of the military's goal to streamline its workforce.
Inouye also warned the Navy that it needs to cut the cost of shipyard repairs and to get jobs done on time.