Captain Morgane and the Golden Turtle

Missable! When you return to Bounty Island from your first trip, speak to Nell right there at the docks to tell her you haven't heard about Bobby. Later, when you have heard about him, return to her and tell her the truth. Later when you meet Bobby, speak to him about Nell. Be careful, this is the one and only opportunity in the whole game to talk to him, so best choose the Nell option as soon as the conversation begins.