I'm not sure who the ignoramus is who wrote this, but at 2,000 tons and 330ft, this is a ship.
And the USA would do well to buy 50 of them.
It's a Frigate. And a nice one too.
I think it has something to do with German naming conventions, which are supposed to make the ships sound small and inconspicuous.
A Baden-Wuerttemberg-class ship (
http://en.wikipedia.org/wiki/F125-class_frigate) is also officially called a frigate at almost 500ft and more than 7,000 tons, while many say it's more of a destroyer.
You are more of an expert: What (in your opinion) would be the appropriate lengths / displacements for a corvette, frigate, destroyer, cruiser, battleship etc.? And when exactly is a boat a ship?
"What (in your opinion) would be the appropriate lengths / displacements for a corvette, frigate, destroyer, cruiser, battleship etc.? "
As you already know there is no agreed scheme of nomenclature and some of it is role based, some of it tradition.
But in my little world:
Corvette - less than 150ft and 1000 tons.
Frigate 200-350FT and less than 4000 tons.
Destroyer - 300-400ft and less than 8000 tons.
Cruiser - 400-500ft and less than 15000 tons. (Obviously this characterizes all the new Aegis "Destroyers" in service today and they should rightly be called Cruisers at 10000 tons)
Boats - All submarines of any displacement and day craft/landing craft/river and littoral patrol. PLUS anything the Coast Guard sails:).
After 15000tons it's all role-based. Carrier or defunct Battleship.
But could you imagine a 45T, 700ft "Balttleship" with all that steel armor...AND 396 VLS tubes?