Since so much of this game is scripted and following scenes require certain scripts to have run, I doubt an invincible ship would work, as it might tell you you've left the area.
apparently it was removed due to crashes, but I hope it returns.. I played to a point where there is a naval mission as a part of the storyline ( and it is pretty damn hard ) toward the end of the game, so I won't play it till there is a inf ship health option
Is there a cheat to make the Ships Invulnerable to damage?
have you enough money to buy the upgrades for the Aquila? I found that a lot of the naval missions are a lot easier once I purchased all the upgrades.....if you don't know how to do that...there is a book next to the harbormaster, just interact with it and buy all the upgrades