Captain Scott Buschman, the Coast Guard’s deputy assistant commandant for capability, knows the ships’ weaknesses firsthand. While he was chief of staff for the southeastern United States and Caribbean district in 2010, 10 of the 12 cutters sent to help after the Haitian earthquake suffered serious equipment failures.

“We can never do everything that people ask us to do,” he said.

The Department of Homeland Security rejected a GAO recommendation this summer that the Coast Guard reduce its overall benchmark for operating hours without major breakdowns. The target has remained unchanged for at least eight years despite the maintenance headaches.

To deal with equipment problems, the Coast Guard has streamlined maintenance operations and is nearing the end of a 10-year, $453 million program to refurbish some patrol boats and upgrade mid-sized cutters until new ships come on duty.

But a new fleet is barely on the horizon despite a recapitalization plan for ships and aircraft the Coast Guard has estimated could reach $29.3 billion, a forecast price that is up $5 billion in the past five years.

The Coast Guard received only three of four new cutters in the biggest class by the target date of the end of 2011. The last of the six planned might not arrive until 2020, the GAO reported.

The new mid-sized cutters have a final delivery date of 2034 - 13 years late. The last of the patrol boats will not arrive until 2021, five years overdue, the GAO said.

The GAO last year blamed the rising price on schedule slippage and cost overruns, such as an extra $1 billion for shore facilities and spare parts for fast response cutters, which will replace the patrol boats.

The Coast Guard also was rapped by the Department of Homeland Security’s inspector general in August for rushing construction and purchase of 12 fast-response cutters before they had been thoroughly tested.

Six boats under construction then had to be rebuilt, resulting in 270 days delay for each one.