Heavy Cruiser Prinz Eugen Should be "Schwerer", as "Kreuzer" is masculine. Author could have been thrown off by Eugen's gender, or by the word "der Schwere Kreuzer" (adjectives decline weakly after definite articles). Also, in case anyone would point out that schwer(er) is an adjective and should not be capitalized, well, the phrase "(der) Schwere(r) Kreuzer" is considered a noun when referring to the ship type. Sort of like "(die) Schwarze Witwe" (black widow) and "(der) Weiße(r) Hai" (great white shark). Basically adjectives are capitalized when they become an integral part of the noun.