Members of the Public and Commercial Services Union (PCS), which includes staff at Shetland Coastguard, were on strike on Monday as part of a 48-hour walkout.
However, a spokesman for the service in Lerwick said the coastguard station was working normally and all distress calls would be answered.
Almost 300,000 civil servants, including 30,000 in Scotland, are striking over proposals to restrict redundancy pay to £60,000. The union claims the government wants to cut entitlements under the civil service compensation scheme by a third from April.
PCS general secretary Mark Serwotka said the proposals would allow the government to sack already low-paid workers on the cheap. The government defended the reforms.