Without the rudder, tiller, and keel, the sloop would drift aimlessly. They are simple objects, but they need a little special handling to fit correctly onto the sloop:
In the File menu, select Append.
Make sure that you are in the Object folder.
Select the Keel, Rudder, Tiller Path, and Tiller Shape by pressing Shift + LMB.
Press the LMB on the Link/Append from Library button.
In the 3D View, press A to deselect everything.
Use the RMB to select the tiller. Check to see that the tiller does not intersect with the sloop's deck. If it does, move it up so that it does not intersect.
Select the Material button in the Properties window header.
Click on the silver ball next to the New button as you did with the mast.
Choose the Deck Material from the menu to apply it to the tiller.
Select the rudder and repeat the steps, but choose Hull Material to apply. Select the keel and repeat the steps to apply Hull Material to it.
Press Alt + C to convert the...