Arbroath lifeboat has been forced out of service after several crew members were suspended in a high-level RNLI probe.
A lack of available operational crew has led to the decision to take the all-weather Mersey-class lifeboat Inchcape off-service.
Cover will be provided from Montrose and Broughty Ferry in the event of an emergency.
The D-Class inshore craft Robert Fergusson remains available to deal with call-outs but fears have been raised that lives could be lost if a serious situation arises.
Arbroath councillor David Fairweather said the situation was of “great concern” and that any delay in an all-weather boat coming north or south to Arbroath could prove costly.
Bosses from RNLI HQ at Poole are thought to be leading the investigation into the allegations which triggered the suspensions.
They are believed to have involved an individual who is not a member of the lifeboat crew – and are not thought to have taken place at the RNLI station at the town’s harbour.
An RNLI spokesman said: “We are currently undertaking an investigation at Arbroath lifeboat station.
“We won’t be in a position to comment on the investigation until it has reached a conclusion.
“Some crew members have been temporarily stood down while the investigation is being carried out.
“As a result, the all-weather lifeboat is currently off service due to the availability of operational crew.”
He added: “The inshore lifeboat remains on service and the area is covered by all-weather lifeboats stationed in Montrose to the north and Broughty Ferry to the south.
“We’re working to get Arbroath’s all-weather lifeboat back on service as soon as possible.”
Town Independent councillor David Fairweather said: “This is a matter of very great concern.
“I have not heard about the investigation and what may have triggered it, but it is very disappointing that something has happened which has prompted the RNLI to come to Arbroath, undertake an inquiry and take the serious action they already have.
“I am pleased by the fact that we have provision from the other stations. But in emergency situations time costs lives and the fact that the all-weather lifeboat is off service is something that leads me to worry there could be serious danger to life.”