Archipelago would be great if the naval AI was smarter than a sack of potatoes (the issues run a lot deeper than you think, short version is that fundamental shortcomings that affect the land AI in small ways become exponentially more prominent when translated to the naval AI, so fixing the naval AI would require addressing some of the AI's most fundamental issues). Also, Civ5's naval combat is incredibly one-note and boring before mid-Renaissance Era, when the one-ship-type-per-era rule is broken by Privateers, and I'd even go as far as to say that naval combat only becomes interesting around early Modern Era, when you no longer have a single, bread-and-butter naval unit like Frigates. Finally, ranged attacks in Civ5 are already incredibly powerful, but the fact that there are no defensive bonuses at sea, ships have a default movement speed of 4 instead of 2, and melee ships cannot move after attacking means that ranged attacks become flatout broken for naval engagements: the player who goes first wins, even when facing a foe with slight numerical superiority. The only reason people haven't picked up on this fact is because the AI is terrible at ranged attacks and people tend to play with Simultaneous turns in multiplayer, where both players essentially get to fire their ranged attacks at the same time.
