THE SPINYAKER TM
Most commercial kayak sails I have tried, seen or read about have numerous drawbacks. Although their costs are generally reasonable, I have been put off by what I consider various defects. Most effective kayak sails involve extensive modifications or additional equipment. These type rigs have masts, mast steps and mounting brackets, some type of rigging or use outriggers. These setups have way too much equipment involved and I worry about what type of problems would arise in difficult conditions or breaking waves/surf.
Of course some of these rigs are used in rough conditions, particularly by some of our kayak brethren in New Zealand and Australia. But I eschew complicated equipment, instead opting for simple straightforward reliable pieces of equipment. (My kayak has no bulkheads, no rudder) I look at some of these rigs and worry about how to deploy these systems at sea in choppy conditions and more importantly how to stow these things when conditions get bad. I worry about the stability and safety of mast tubes through my deck and glassed in mast steps on the bottom of my kayak.
The Spirit sail pictured on the left does manage to avoid a lot of these objections with a simple mounting in front of the cockpit and no rigging to support the bending freestanding masts. But my objection to this design is that most of the center of effort of this is sail is up high. Also the sail tends to dodge around in strong shifting winds. With that much force up so high, stability is a problem.
So I started thinking about my own design. It needed to be simple as I am no sailmaker. I wanted to be made of cheap but sturdy, non-corosive materials obtainable almost anywhere. It needed to be stable, easily deployed, ditched, doused, stowed and transportable. Sounds impossible doesn't it? But I think what I came up with works extremely well. Here it is in action in Baja Sea of Cortez on a rental Tesla.
The design is based on an old time spinnaker design called a Jimmy Durante spinnaker. From the side it is obvious why the shape is given that name. It looks like a big nose. From the front however it looks much like a traditional spinnaker.
This design has many advantages, the foremost of which is it is extremely easy to make. There is only one seam, the one along the top and there is not much stress on that one. It is also very stable. It does not dodge around in puffy shifting winds. Its center of effort is much lower than the inverted triangle shape of the commercial sails.
To launch the sail, I pull it out from under the deck rigging, join the two parts of the mast together, attach the carabinier to the deck rigging, position the sail in front of me and pull back on the two horizontal pipes. The sail comes up into the wind and supports itself because of its shape. I hold the paddle in my hands in case I need to brace. If I need to ditch the sail I just let go, letting it fall to one side . I can retrieve it when things are back under control. The sail does not catch water as it collapses astern of the kayak attached by the carabinier on the deck rigging right in front of the cockpit. If it is necessary to ditch the whole thing all I have to do is unclip the carabinier. As I bring it up out of the water, any water runs out the hole in the nose.
In 15 knot winds a sail of this size will allow you to stay up with strong paddlers paddling continuously. For regions with lighter winds you may want to make the sail bigger by using more sail material. Because the height of the sail is fixed to the bolt width of the material, a bigger sail will be wider, not higher. I think that would be good. Another option for more sail area would be to not fold and cut the sail on the bottom. That would lower the point of attachment for the side booms and make more sail area. The sail may not draw as well as the upper boom ends would not be at the same height as the stabilizing hole. You would have to experiment. (Movie of deploying sail in backyard in 15 knot gusts.)
I keep my paddle in my hands and hold onto the booms with a couple of fingers. That way the paddle is always ready for a brace as required. The sail supports the weight of the paddle so I do not have to hold it up. You can adjust the amount the wind supports the sail, mast and paddle by leaning the sail back or forward. The plastic booms do not conduct the cold or heat so holding onto them is no problem in a wide range of weather. With the boom and mast pipes sealed with insulating foam, the sail rig floats, carrabinier and all
With a ruddered kayak I was able to sail in all conditions from 90 degrees across the wind to straight down wind. To sail across wind simply angle the booms so that the sail still catches the wind and stays full. It's not fast across wind and you won't keep up with those actually paddling.
For kayaks like mine without a rudder, the sailing is a little more difficult as it is impossible to stay on course using leaning. In any case that is too tiring. Course corrections can be made by dipping the sail to left or right to drag one end of the paddle in the water. Of course that slows you down, but since no effort is required to speed back up, it is not too bad.
One other option I want to experiment with is to make a new sail out of Tyvek, the plastic sheeting used as moisture barrier in new house construction. If I could figure out how to make a sealed seam across the top that would be sturdy in a marine environment I think it would be an excellent and really cheap option. The nylon was the most expensive of the materials.
Another advantage of this sail is that it is less than 36" long when the mast is in two pieces so it fits in my luggage for expeditions. It is also cheap enough to just junk and rebuild if luggage space on the way home gets to be an issue.
The biggest problem with the sail is you can't see anything when it is deployed. Of course it is easy to fold up and take a peak every now and again, but the view is real boring. The second biggest problem is that deploying it from under the deck rigging and sticking the two mast parts together takes two hands, meaning that the hands are off the paddle so it can only be raised in relatively benign conditions. Then again if I am likely to be going over if I take my hands off the paddle, I am not likely to be wanting to RAISE the sail anyway.
2007/05/06 - I had the sail out in 20 to 25 knot winds, which frankly is too much for this sail. The plastic pipe mast was bent over at a 90 degree angle and the sail laid on the top of the the kayak. However, the sail was still effective, giving me all (and more) propulsion than I wanted. It was easy to deploy and put away again. Several times when sailing cross wind I had to let go of the boom pipes in order to keep from being pulled over. The sail simply collapsed into the water from where it was easily retrieved. Altogether a very satisfactory performance in difficult conditions.
The sail is held up by four pieces of 1/2 inch PVC water pipe, two pieces of which join to form the mast. The sail is made of 2 yards of 1.9oz/yrd nylon obtainable from any fabric shop. I used uncoated nylon but I would recommend using coated nylon as it does not require a heat knife when cutting the material to keep the edge from fraying. ( I used a soldering iron which worked perfectly.) I used 1 inch wide nylon straps to attach the sail permanently to the four corners through PVC pipe tees. A short piece of nylon rope at the bottom attaches the sail to the kayak with a cheap aluminum carabinier. With the mast in two pieces and the booms folded along the center line, the sail fabric rolls around the four pipes for easy storage in luggage or the front deck. The sail cost $18.00 in materials and I made it in one afternoon.
2 Yards of 60" wide coated 1.9 oz/yard ripstop nylon.
2 10 foot 1/2 " OD PVC Water pipe
6 PVC 1/2" 90 degree tees
2 PVC 1/2" joiner connectors
1 PVC 3/4" joiner connector
3 feet 1" nylon straps or 3/4 " polyester straps
1 mini carabinier
2 feet 1/4" nylon rope
1 spool carpet thread or waxed sail makers thread.
1 heavy sewing needle
1 PVC Cement
1 Can expanding foam leak insulation (Optional)
Helpful additional equipment - sewing palm - sewing machine - soldering iron if not using coated nylon.
Sources: The fabric was obtained from the local fabric store (JoAnn's Fabrics) and the pipe and cement from Home Depot.
Lay the fabric out on the floor with the longer length horizontal. Take the left edge of the fabric and fold the piece in half to the right edge. You now have a doubled piece of fabric 36" wide and 60" high with a fold on the left and two edges on the right. Take the upper left corner and bring it to the mid point of the piece and far enough down so that the fold meets the upper right corner. Do the same with the lower right corner. You should now have a parallelogram. If not, you grabbed one of the corners on the wrong side. Mark or crease the folds and cut along the mark.
From the new upper left hand corner, fold the corner in at an angle bisecting the corner angle until the folded edge is 6" long. Mark and cut along the folded edge. This leaves a small hole in the sail that allows the sail to be stable. It also allows water to drain from the sail if you have to ditch the sail in a hurry. Do not leave this feature out. You are now done with the cutting.
Sew the upper edge together. I used an flat felled seam for strength. I hemmed the other sides but I now think that that is not necessary. Make you own decision.
Set the fabric aside.
From the two 10 ' sections of PVC Pipe cut four 34" pieces. Optionally, use the can of expanding foam leak insulator to seal the ends of each piece of pipe. This will ensure that the sail rig will float.
(HINT: assemble everything without glue first so you can see how it goes. )
On two of the sections, glue the 1/2" joiner connections to one end of each pipe. Select one of the pipes and glue the 3/4 joiner connections over one of the 1/2 " joiner connections. This pipe will now be the bottom of the "mast". The other piece is the top.
On the remaining end of the two parts of the mast glue on the PVC tee connectors with the pipe sticking in the center opening and the open barrel at right angles to the pipe. On the other two pieces, glue the tees on both ends of each piece. The open barrels of the two tees should be at right angles to each other on opposite ends of the pipe.
All that remains is to attach the pipes to the sail fabric. Bring the teed portion of the lower part of the mast together with one end of both of the pipes with two tees on it. Using a 10" long pieces of strapping, pass the straps through the open barrel of the three tees and cross the ends together. Place the corner of the nylon fabric in between the straps ( a recent modification ) and hand sew them together. Using 6" pieces of strapping, pass them through the tees, cross the ends and secure the corners of the sail fabric to the pipes. Note the crapy hand stiching in the photo below.
(Optional: For extra strength I reinforced the larger 3/4" joiner connector by wrapping it with cotton string and soaking it in polyester varnish.)
Here are some pictures of the assembly details.
Bottom of mast where two booms are joined together by strapping sewn onto the sail fabric
Nylon rope with carabinier connects the sail to the deck rigging. Note complete lack of sewing skills.
The mast connection with reinforcing.
Make your own sea anchor.
Make your own Greenland paddle.