Great Yarmouth's coastguard centre, which covers the Lincolnshire coastline, has closed as part of the Maritime and Coastguard Agency programme of modernisation
The agency said full operational responsibility had been transferred to Humber coastguard.
It said there would be no reduction in crews, lifeboats or helicopters. The MCA added no compulsory redundancies have occurred out of Yarmouth's 25 staff.
Chief coastguard Peter Dymond said: "Safety is our top priority and I am confident the same high-quality search-and-rescue service will be maintained throughout.
"There will be no reduction in front-line rescue resources. The availability of lifeboats, rescue helicopters, Coastguard Rescue Teams and other rescue facilities in the area will be unaffected.