Too many coastguards were leaving the service, the report from the House of Commons Transport Committee said.
This loss of staff was "creating a risk that talent and expertise will haemorrhage", said the committee.
Under Government plans, modified from earlier proposals, Forth coastguard station in Scotland has already closed and it is planned that progressively over the period to 2014/15 the Clyde will close along with several in England and Swansea in Wales.
The report added that the committee's main concern was that the Government "had not yet fully explained" how the new system – which involves some coastguard centre closures – would work.
The MPs' report was also critical of Shipping Minister Stephen Hammond who, when appearing before the committee, had said that people in the coastguard service were happier than the evidence presented to the committee suggested.
Mr Hammond also said that he had not been to any of the coastguard centres.