It's now time to flatten the transom. By setting control points very close to each other, you can make pretty sharp corners. Try it by executing the following steps:
Press A to deselect all vertices. Press B and use the mouse to select the control vertices for the transom on the right side of the control object.
Press E to extrude. Press Enter. Then, press S, 0.95, and Enter.
Press Tab to go into Object Mode.
Press the MMB and use the mouse to rotate the view so you can see that the transom of the sloop has been flattened.