I read this piece, over and over, and I feel too slow at grasping the meaning T_T
But I think is about the choices one has to make, How we have to choose in life. For instance, the Shipwright seemed to want the three things, the north star, the dark red leaves and the lighthouse. But what I gathered, is that it seems they were located in different regions, yet he would have liked to have the three.
hmm.. I don't know the poem doesn't sound that simple, I feel there's more to it.