Today's industrial action at Liverpool Coastguard station is part of a week of planned disruption.
Staff plan to down tools again tomorrow between 11am and 12pm, with more strikes each day until June 15.
The Public and Commercial Services Union believes lives will be put at risk if the base closes.
Staff at the Liverpool Coastguard station have started a series of rolling strikes over plans to close their base.
Read the full story– Mark Serwotka, general secretary, Public and Commercial Services Union"We have always had grave concerns about the government's proposals to cut coastguard stations and staff, and we know this is shared by people in our coastal communities.
"We believe these cuts could put lives at risk, and we want ministers to abandon the plans and talk to us, the public and seafarers in a genuine effort to establish the kind of coastguard service we need, and to invest to ensure the proper resources are put in place."
Staff at Liverpool coastguard station are starting a rolling series of strikes.
They walked out between 3am and 4am today.
The station, which is based at Crosby, is one of nine the Government plans to close.
