Agencies|responsible concerning upholding maritime regulations together with defending vessel ships against marauding.
I also need to consider part of speech. Nouns, verbs, adjectives, and adverbs each need their own set of synonyms. For example, "shadowy" can be replaced with unknown, which are all adjectives fitting the description of an elusive group. War on the Sea-DARKSiDERS
Same process here. Replace each word with three variants, proper nouns stay. "shadowy" can be replaced with unknown