The Royal Boat is the use of transportation you, Buddy, and Lyndsay use to travel throughout King Roland's kingdom. It was previously owned by harbormaster Barney Cull until he gave it to you after you built him a home on Capital Island.
Buddy: I spy something with my little eyes that starts with [player name].
Lyndsay: Is it [player name]?
Buddy: Omigosh! How did you know that?
Lyndsay: ... Lucky Guess.
Buddy: Hey, [player name], why do you get to steer the boat?
Lyndsay: Oh, I don't know, maybe because you get seasick and I hold the maps.
Buddy: Oh... Hey, Lyndsay, why do you get to hold the maps?