Canoe Sail




About: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of, manufacturers of "3D Printer" output devices. His detailed drawings of traditional Pacific...

This 5 meter spritsail rig makes a canoe go really fast.
It's easy to build, easy to control, easy to put up and take down. It tolerated gusts well and can be tuned for really light winds also.
I use an aluminum sign as a leeboard and steer with a paddle.

If you don't have a canoe yet, try these complete plans for an outrigger sailing canoe.

action photos by Star

Step 1: The Sail

Is made from a brown polytarp.
It's heavier material than such tarps are usually made these days.
Polytarp is a fabric woven from strips of polypropylene that's then heat-laminated to a sheet of polyethylene.

Each side and corner of the sail has a traditional name.
The sides are called Foot = bottom, Head = top, Luff = front, Leech= trailing edge.
The corners are called. Peak , Throat , Clew, and Tack.

The Leech and Foot are the original edges of the tarp. That saves some sewing.
The other edges are cut, folded over and sewed.
Sometimes I'll put a "bolt rope" cord inside for extra strength.
I used a regular home sewing machine with the thickest needles I could find for it.

Here are the dimensions of the sail:
foot: 101"
leech: 134"
head: 71"
throat to leech distance: 55"

This sail is made for a mast that rakes backward at a 15 degree angle.

If your mast is vertical you you should use the other sail drawing, or your clew will be too high. The leeboard stays in the same place but the mast partner is moved a few inches back.
I reduced that version of the sail to 5 sq. meters, which wise Canadians have decreed is the perfect size for a canoe sail.

Step 2: Leeboard

The leeboard is an aluminum street sign 2 feet square. The corners are round and there are two holes in the top edge near each corner. I tied cord to these holes and tied the other end of the cords to the canoe's center thwart. I wrapped some innertube around that to make sure it wouldn't slip.

When I tack and turn the canoe so the wind is on the same side as the leeboard it swings up.
I pick up the leeboard and toss it into the water on the other side of the canoe.

The leeboard should be just in front of the center thwart to balance this sail well.
Then it's very easy to steer with the paddle.

When things are right the canoe will turn into the wind when you pull the paddle out of the water.
You'll have an easy time steering and water pressure will hold the paddle against the leeward side of the canoe. This set of conditions is called moderate "weather helm".

Step 3: Sprit

The long diagonal stick that holds up the high corner of the sail is called "The Sprit".
Hence the sail's name, "Sprit Sail".

My sprit is a cypress pole from a Florida swamp.
I cut it from a standing dead cypress sapling to use as a push pole.
You don't need a push pole if you're sailing and vice versa, so it's nice to use it for both jobs.
This pole is very light wood but it's springy. It's about 2" thick at the thick end and just over 1/2" thick at the tip. Mine is about 10 feet long.

At the thick end I attached a fin Seminole style to steer the boat at the end of the push stroke, and to paddle in spots of deeper water.

Step 4: Mast, Mast Partner, and Mast Step

My mast is a spruce pole I cut in the Maine woods, also from a standing dead blighted sapling.
It's about 12 feet long, 1.5" thick at the top , 2.25" thick where it passes through the mast thwart.
The mast thwart, also called the "partner" is a board with a hole in the middle that holds the mast up.
I added this board across the canoe near the bow of the boat. It's attached with epoxy, screws, and lashings.
I wanted to make sure it would stay put.

The base of the mast tapers down to 1.5" thick. It sits in the "mast step", a block of wood I epoxied to the floor of the canoe just ahead of the mast thwart. The mast step has a socket carved in it that's just big enough to accept the base of the mast.

Step 5: Simplest Sail

It's traditional to agonize over sail shape.
If you're in a hurry a rectangular 5'x7' army poncho will work well as a spritsail on a canoe.
The extra stick at the bottom isn't necessary.
It's called the "boom" because of the noise it makes when it hits your passenger in the head.

This sail is tuned for very light wind. When you tighten the "snotter" to raise the sprit as seen here, that puts belly into the front part of the sail. Good for light winds. In heavy winds you can remove the sprit entirely. The peak of the sail flops over and doesn't draw.
That's called "scandalizing" the sail. It looks bad but it works fine. It reduces the sail area by almost half and the area that's left is very low and easy to manage.

Notice the sticks the canoe is sitting on. If you make a little stick railroad like this you can drag your canoe over rocks without harm.

Here's a cute old book with a discussion of other types of sails for canoes.



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    35 Discussions


    3 years ago

    I made it


    4 years ago on Introduction

    I love your rectangular 5'x7' army poncho as a Spritsail

    From what I can tell, there are only 4 grommets on your poncho sail?

    One for each corner?


    8 years ago on Introduction

    hey man this is a great sail but do you think it will work on the east river in ny?
    i take a trip every weekend from brooklyn to governers island

    1 reply

    Reply 8 years ago on Introduction

    It'll work anywhere there's wind and water but I'd get used to it on more sheltered water then a river as busy as the East. Also, there's currents you have to keep deal with. Don't want to have to learn too much when you're out on water that's deeper then you are tall.

    Like pretty much all traditional rigs the sprit sail isn't as good hard on the wind as a marconi but it's a whole lot cheaper then the marconi, you can build it yourself, it's a good sail for something like a canoe without a lot of stability and where it really shines is when you can loosen the sheet a bit.

    From close reaching through running a spritsail, and most traditional rigs, are a delight - fast, comfortable, easy to handle and, of course, they look great.


    Reply 8 years ago on Introduction

    I harvest them off the street after hurricanes hit. Otherwise they just get thrown away by the trash guys.


    Reply 9 years ago on Introduction

    Hello I went to my local metal scrap yard dealer. He had a couple laying around, a 2x2 sign, pretty heavy material cost me 5 bucks. Cheers, whitedab.


    9 years ago on Introduction

    How do you sail this without the canoe tipping over? Are you able to balance it with just your weight?


    9 years ago on Introduction

    This is great! I just bought a Walker Bay 8, and don't wish to spend $1000 for a sail kit, so I was looking for ideas. This will make a great starting point, especially for the sail dimensions! Well done!


    11 years ago on Introduction

    Awesome sail, would thick contractor type garbage bag or plastic drop cloth be good for this sort of sail? I have rescued tons from the dumpster at the storage facility, and I am looking for ideas. I have made some kites for local kids so I know they will catch wind, but I am not sure if they would hold up to the rigors of sailing.

    1 reply

    Reply 9 years ago on Introduction

    plastic would tend to stretch, the plastic in garbage bags is stretchy on purpose, so as you were sailing it would stretch more and more, also the seams would cause problems as the tape or other attachment methods would make flattened sections in the sail. with the a lot of time you could make sails, but they would break down quickly compared to polytarp or tyvek.


    9 years ago on Introduction

    I've spent a fair bit of time over the last couple of days looking at your Sprit Sail rigs for your canoe. I have to say that I'm very impressed! I have a commercially produced 'downwind sail' which has served very well for many years, but it requires to be held by a bow paddler and has a number of obvious limitations. So I've been thinking more about a traditional sail rig for my Old Town Penobscot 17. I have to say that a sprit was getting close to the top of my list of possibles and was searching the web for details of the snotter when I came across your post here. A couple of questions regarding your rig if you don't mind. I can see what look like reinforcement points on the luff of your sail but have been unable to see whether you lace the luff to the mast or not. Do you use a lacing or regard it as unnecessary? Do you find the length of spars a problem for when the sailing rig is stowed in the canoe, I'm thinking of when you have a bow paddler. Or is this rig for solo use mainly?

    3 replies

    Reply 9 years ago on Introduction

    The spritsail in this ible is pretty big. I made it to use in Florida in light winds or with an outrigger. For a typical monohull canoe you'd want a much smaller sail. 4 meters maybe, with reef points to reduce sail if you need to.

    There are grommets to lace the luff to the mast, but I don't use them anymore. With moderate luff tension the luff just lays along the mast and doesn't flutter. With different cloth or a longer luff you might need to lace it. The luff is pretty short here. The sprit is LONG. That's okay, becuase this sprit is a push pole
    I use in shallow water when there's no wind. So I wouldn't mind having the pole along anyway. A lugsail works about the same as a spritsail and has shorter spars. You could lace a yard to this spritsail and rig it as a lugsail.

    Bear in mind a lugsail extends in front of the mast, so mast placement won't be the same for lug and sprit rigs. If you decide your mast is in the wrong place, you could switch rigs.

    Here's the sailplan for a lugsail that's about the right size for a tandem kayak or canoe. Don't use the wishbone boom, that's only there for skateboarding. Use a straight boom or use it loose-footed.


    p.s. wrt mast placement, if you're using leeboards, that gives you much more leeway (har har) in where your sail's center of effort is located over the boat. Just move the leeboard(s) fore or aft to properly balance the sail.


    Reply 9 years ago on Introduction

    Thanks for the reply. The sail in this ible is pretty big, but I was thinking of using the smaller of the two you detail, which works out at about 53 square foot compared to many sails I see, over here, which are 45 square foot, I think. I also thought a couple of rows of reefing points with using one row to make a working sail area and shaking out this reef in light airs. For the sprit, I have a fibre glass pole which is usually with the canoe for poling and splits in two for storage, it's also an integeral part of my tarp system. This pole is twelve feet long and looks, from the measurements I've made, to be a good length for the sprit. I've an eye on a windsurfer mast on e-bay at the moment. It has a damaged top section but looks like a potential mast for this project. It also splits in two so should alleviate my stowage concerns. I'm planning on the mast partner going behind the stern seat, so when in sailing mode that becomes the bow and should be better whether solo or with a paddling partner, or indeed with the family. This is another appealing feature of this rig where a balanced lug requires the partner to be closer to the centre of the canoe, as I understand it anyway. Leeboards are a must for me as I'd like to enjoy a good reach and hopefully make some progress to windward, though in many cases it'll probably be easier to paddle into the wind. I just need to track down a suitable road sign. A call to the local council depot might be a good start. Otherwise, I've plenty of ply in various sizes which might suffice. Thanks again, Al


    10 years ago on Introduction

    Its called a boom because thats the Dutch word for tree. And dingy is the Dutch word for thingy.

    1 reply

    Reply 10 years ago on Introduction

    wij Nederlanders noemen een "boom" een giek we in holland call a boom a "giek"