Detailing the sloop, and adding a door and portals
This book cannot cover everything. It would be neat to add an interior, an anchor, and other details. However, there is still much to cover. So here are a couple of bonuses for your hard work and persistence: a line for the mainsail, which you can copy and use to create other lines for the sloop; the door; the portal window; and a nice brass portal frame.
Note
For your reference, the 4909OS_09_Portal_and_Door_Assembly.blend
file has all the parts, textures, and instructions in the Text window on how to create the door and a glass portal window.