Global Firepower has been known to throw up false information. Russia has 701 ships? How can they afford that when they barely pay their ground forces $5 a month? Not to mention the cost of upgrading existing systems in the Army and Airforce. At the moment, the Russian Navy only has 80 - 100 ships, and most of those are in ports.
The North Korean Navy consist of 22 Romeo class coastal/patrol submarines, 4 Whiskey class coastal/patrol submarines, 22 Sang-O class coastal infiltration submarines, + Osprey class semi-submersible infiltration craft plus numerous patrol boat ships and missile boats. Nothing major, but they can prove to be an annoyance. Most people put the NK Navy at around 300 ships total. Mostly outdated stuff however.
The United States Navy does not consist of 1,800 Ships. The US Navy consist of 500,000 men, and 282 ships. Not to mention, I believe, 3,000 Aircraft.
I haven't done any real research on the Chinese Navy. But I doubt its that big.