Joe's Rock Band — Juliet Bates

The story is about a boy called Joe who lives with his granny in a house on the top of a cliff.
One night, Joe sees the bright light of a boat out at sea and he runs out of the house and into the garden to peer over the hedge to see a golden boat arriving at the edge of the beach.
Then suddenly, the light from the boat goes out and Joe is left alone in the dark garden on the cliff top, wondering if the golden boat will still be there in the morning.
The next day, when Joe is on the beach with his dog, Ted, he meets the Cormorant and the Puffin who are the mystery sailors of the boat. They invite Joe and Ted the dog, to go out for a sailing day.
Joe is so happy on the sea fishing and sailing and singing. However, the Cormorant warns him that they must keep watch for the sea dragon who will steal their fish. At that very moment the dragon strikes and suddenly the boat is awash with sea water and very nearly sinking. They all struggle home with the fish gone.
That night Joe has a look in his granny's old seaside book and reads that dragons really hate loud music.