What is the boat for in harvest moon ds?

When you have completed the billionare cheat keep the money until spring. At the beginning of spring Thomas the mayor will tell you about this island and asks if you will buy it. say yes and he will leave. Go to the beach and go to the boat. Press A. It will ask if you want to got to the island. Say yes. You will have your own island. If you ring up Gotz the woodcutter there will be an option saying cottage. Build it and on the island you will have your own island and a cottage on top.

You will have loads of money left if you think its alot. Don't be cheap!!!! You can fish there as well.