On paper, the two most powerful naval forces in the world, by a long shot, are the United States and Russia (North Korea, China, and Iran are some of the most notable potential naval threats).
But, an analysis of the Russian navy suggests that a large share of its ships are broken or seriously outdated, and that the pace of operations for the ships that they have is very light. For example, the analysis claims that less than half of Russian Navy ships are operational, compared to 85% of U.S. Navy ships. North Korea's navy suffers similar issues.
In other naval news, the United States Navy has decided to rename the Littoral Combat Ship as a "Frigate", now the last of the Oliver Hazard class of frigates has ended its active duty service in the Navy, in an effort to honor "naval traditions."