The Navy’s troubles with keeping ships maintained and at sea have only worsened in the last several years, resulting in a less-ready force when the service is looked to as the first line of defense against China, the Government Accountability Office reported this week.

The service’s inability to keep ships running is also having serious effects on the operations of the Marine Corps, which relies on Navy ships to transport and position them near mission areas, to the frustration of officials in that branch.

Overall, the watchdog agency report released Tuesday found that while the Army and Marines have managed to keep up or increase the readiness of their troops, the Navy’s sea forces have been on the decline — with some areas worsening for more than a decade.