4 Sided Sails For The PDRacer Sailboat
Balanced Lug
In the picture the boat on the far left has a lateen sail, the one in the middle has a balanced lug that uses a high angle yard. The blue boat on the far right has balanced lug more of a moderate angle yard.
The balanced lug is a very popular type of sail used on home built boats. They are simple to make, simple to use, and puts a lot of sail area on a small set of spars. Basically it is a 4 sided sail that has a stick on the top edge (yard) and a stick on the bottom edge (boom). You hoist it from a line tied to the yard. Both the yard and boom extend both fore and aft of the mast, and so it is called a "balanced lug", even though it really isn't balanced on the mast.
One of the things I have noticed about balanced lug sails is they can be made in a variety of shapes and sizes. The yard angle is a big variable that various people employ to get a certain look from the sail. The picture to the right is Marc Blazer's #173 "Bloody Splinter".
Here are some great essays from Jim Michalak further explaining balanced lug sails:
lug sail rigging instructions
lug sail reefing instructions
sail area math - sizing your sail
While balanced lug sails are very popular to use for recreation, they are not the most competitive sail for racing. For more info, see a comparison of 3 sided VS 4 sided sails on the sailboat racing and performance page.
Standing Lug
Very similar to the above lug sail, but notice how the tack (forward bottom corner of the sail) is attached to the mast. This sail just happens to be made from a rectangular tarp, but often they are made with similar shapes like the balanced lug.
Sprit Sail (4 sided, traditional)
This rig has the sail laced to the mast, and a stick that goes diagonally up to hold the peak of the sail. This one has a sprit boom also, but sometimes the sail is used without a boom.
As you can see in this picture, you can even use a perfectly rectangular tarp for your sail.
Gaff Sail
This sail has it's leading edge (luff) attached to the mast, and has a stick along the top (called a yard).
Note that this duck also has a jib sail attached forward of the mast. If you look a little closer, you will see it has a bow sprit made from a hockey stick. Hehehe....
