Heroes of the Seven Seas

Story related, cannot be missed.

This trophy will be earned after doing a brief tutorial. You'll destroy some rocks on your right and then your left side. You will be able to move your ship for the first time at sea with . There's a person named Dai shouting "help me!" as he's floating in the middle of the sea right in front of your pirate ship. Drive closer to him and press the button to save him and he'll join your crew as the trophy unlocks.

It should be noted that you're not really required to save him. You could drive past Daidai and destroy the ship. Daidai seems to automatically join your crew anyway even if you didn't save him at sea. This will also cause the trophy to unlock if you chose to go after and destroy the enemy ship.

Please see the To the Black Market trophy so you don't miss it on the way to the black market.