In chapter III you need to get all three ships.
*** Spoiler - click to reveal ***During the auction there are several ways to get a ship. You can outbid your opponent, if you have enough money. You can defeat them in a duel, if your Pistols & Swords skill is high enough. You can use your Parley skill. Or, if your Skullduggery is high, you can set in motion your devious plan.
To obtain the Sea Queen you need to either politely summon the spirit with your Cambiar, or ask Tinima to do that for you. Then the bulletproof options are "What makes you think I'm asking?" and "Do let's be reasonable about this!". Though you can try other ones, if your Parley or Sailing skills are high enough.