When progress is made a ship will appear in the dock, Kapp'n will then lead you to the tropical island for 1000 bells, while on the ship, Kapp'n will sing songs about random subjects. He will usually ask you something halfway through the ride or complement you.
To skip his songs, repeatedly press the A button, this is useful when you are in a hurry. Once you return to the island he will say you look a bit different but will then end with "Must be the sea madness". When you skip his songs by pressing the A button he will say stuff about you being sick and needed to listen to his song if you want to feel better or no need to rush before you quickly arrive.