This article is written by George Steele and a kind contribution to this website. George has a strong passion for free sailing boats and I told him I could never write such a good article as he can on this topic – and so he did. You will find him in most RC Sailboat forum’s if you have any questions on this topic or contact me and I will forward your email.
Free sailing is a pleasant pastime to do with your grandchildren if you have the right pond.

Picture from U.S. Vintage Model Yacht Group
It used to be pretty easy to buy a small wooden sailboat, sloop rigged was best (one hull, one mast, one large sail and one small triangular sail “up front.”) (Of course you could build one, but you would have to use your imagination and some luck to find a proper weight to fasten to the bottom of the wooden keel that you attached to the bottom of the boat. A good sized bolt would be good.)
The “right pond” was a medium sized one that you could walk around in 15 minutes or less and has solid banks without lots of reeds or cattails. A public park pond with stone or concrete edges would be good.
These boats could sail close hauled (heading about 45 degrees from the wind) or even directly across the wind- 90 degrees from the direction the wind came from), Usually the big sail behind the mast had a thin wooden “stick” attached to the bottom of the sail (and it was called a “boom.”) The string that was attached to the after (back) end of the boom was called the “main sheet” and you would adjust the boom so it stuck out maybe 30 degrees from the fore and aft centerline of the boat.
Now the “trick” about sailing well was to adjust the jib’s sheet so that the jib would not “luff” (shake) while the big (“main”) sail might just luff a little. With the sails adjusted properly the little boat would sail a pretty straight course across the pond.
Thus if the wind was blowing directly from North to South you could sail northeast or northwest. You could also adjust the sheets of the two sails so you could sail directly east or west. However, problems arose when you tried to sail further south, and you could not sail directly down wind.
Now this is NOT just something we did long ago. You can search on the web and find these boats for sale today. The only thing that has changed is the price! (Just as the price of a candy bar has jumped from five cents to a dollar.)
Try it, you will enjoy it.
PS: If you want to know more the U.S. Vintage Model Yacht Group has a very detailed description on free sailing
PS PS: George gave me the book tip for people interested in building model sailboats, which provides as he explained a “more accessible and clear description of the ideas and methods of modern naval architects”
The book is called “Yacht Design Explained …” by S. Killing & D. Hunter