Okay, the user wants me to translate "combat vessels" into Japanese. Let me think about the correct term here. "Combat vessels" typically refers to military ships used in warfare. In Japanese, the standard translation for this would be 「戦闘艦」. I should make sure there's no confusion with other terms like 「軍艦」 which is more general for warships. Since the user specified to translate into Japanese and provide only the result, I'll just output 「戦闘艦」 without any extra text.