'Polykopa' = warship?

[Nathan Ross]

Can any Greek specialists confirm for me whether or not the word polykopa (πολύκωπα), or 'multi-oared', invariably refers to a seagoing warship, presumably of the banked variety (triremes etc)? Or might it ever be used, at any point in Greek or Roman history, to denote other kinds of vessel, either civilian or perhaps riverine?

Thanks!