The Kayaksailor sails make me think that a batwing type (inspired) sail would probably have good upwind performance for us.

Am I right in interpreting the Kayaksailor to be an adaptation of batwing sails to make it more able to be reefed (and of course stowed, in this case)?

We are considering a junk rig for easy fast reefing to adjust to a wide range of wind speeds and for safety reasons, and because it is relatively easy to fabricate (I know how to use a sewing machine and have fabricated tarps and the like before).

I am concerned though that a junk rig may potentially not work well enough upwind with a small boat like ours?

We found Tim Padfiel's junk rigged kayak here:

http://www.padfield.org/tim/kyk/sail/junksail_01.htm

and here (second page of his article):

http://www.padfield.org/tim/kyk/sail/junksail_02.htm

who has also posted in the Junk Rig Forum here:

https://junkrigassociation.org/general_forum/7240978

who by the sounds of it seems to not have gotten acceptable (for us) upwind performance with his junk rig on his kayak.

If you read his article above and look at his photos - can you see anything that he might have done "wrong" that would have resulted in such poor upwind performance? What could we do better?

Or is a junk rig simply not likely to work upwind to any practical degree on such a small boat?

He seems to have sewn his sail flat.

From quite a lot of digging through the interwebs and historical material here and elsewhere, it seems that there are good arguments for rigid, not flexible, battens - since if they are flexible, the camber of the sail increases with higher wind speeds, which is exactly the opposite of what one would want.

So I am thinking: Rigid battens with a cambered cut of each panel. Does that make sense?

Obviously no one can really be sure about the following, but what is your guess, do you think we have a chance of traveling upwind at an actual path of no more than maybe 60 degrees off the wind, if we use cambered panels?

What else optimizes the upwind performance of a junk rig?

Since the rudder control pipe only runs along one side of the boat, we steer with one foot - pushing and pulling on a "pedal" that covers the bottom and the top of the foot at the same time.

The mast doesn't go anywhere, it is rock solid. There will be a second ratchet strap approximately where the carrying handles on the side of the boat can be seen. Additional triangular bracing will be added from the mast foot "wall" to the rear, along the side of the chilly bin. I am considering to add a traveller aft of the chilly bin - seeing that the bin limits how low the boom can be, there won't be a lot of space above the chilly bin for a boom vang, which therefore might not be all that effective.

Hi everyone,

first post, I'll jump right in, hope that is ok - if I should be using these forums differently in any way, please don't hesitate to let me know! Thank you very much for providing them.

I hope a sailing kayak will be taken seriously by some people here who know more about sail design than me - I could use some help with brainstorming for that part of our current project, and would really appreciate any input you might have for us.

My eleven year old son and I are using a triple seater sit on top kayak as a platform for dolphin watching, snorkeling, free diving for paua, fishing, and more; generally along the coast, but not infrequently in somewhat remote places and / or places where landing is out of the question, and on occasion a good mile or so off shore. As I am writing this I am shaking my head again in disbelief, not for the first time, about how lucky we are to be living in such a place...

Just in case you wonder, I humbly believe that we do know what we are doing, and importantly where our limits are. I have a background in white water kayaking, swift water rescue, scuba diving, as well as sea kayaking, and in addition to knowledge and skills we are very well equipped, including but not limited to warm wet suits and VHF radios and a 406 MHz beacon carried securely in / on our life vests. We also let reliable friends know before we go out what our plans are and when we intend to report back with them. We are both very comfortable on the water, in the water, and under water - when dolphins came up to our boat for the first time in early 2019, about a mile off shore, my son instantly jumped into the water, in about a metre and a half of swell... one of the reasons we chose a sit on top, getting back in is easy! We are also meticulously picky about weather, wind, and sea state forcast when doing our trips. Our priority number one is to come back in one piece, always. So while we have never seen any other sit on top kayak in some places that we go, and not many closed sea kayaks either, we are playing it very safe nonetheless.

We are currently in full swing of kitting the boat out for sailing - and I don't just mean downwind, I mean actual sailing. Our goal is not more speed, but a bit more reach than the seven to ten miles that we usually do on our day trips; and to have more physical energy available both for our activities at our destinations, as well as as backup energy in case something doesn't go to plan with a trip.

My son wanted to do this as a learning project, partly for the design and build process, partly because he wants to learn some basics of sailing, and partly because he wants to have more adventures on the water - and I have happily embraced his suggestion.

So after a few weeks of chipping away on this with our brains and hands, the pictures below show where we are right now.

We have chosen an unstayed mast in a rather hefty mast foot in order to minimize any standing rigging. Less is better on such a small boat; we often have snorkeling and other gear with us as well, plus the chilly bin for fish and paua, and we move into the water and back into the boat often, so space to move around without getting tangled in lines too easily is important.

After some thinking we are currently leaning towards a junk rig inspired sail plan. Some of our reasons for that are quick and easy reefing so the sail area can easily be adjusted to the wide range of wind speeds that we can encounter here within a single day; and relatively easy design and fabrication of the sail itself. We are also leaning towards cambered panels, maybe with the exception of the topmost one or two.

One difference to typical junk rigs would have to be that the sail can not extend more than maybe five or ten centimetres at most in front of the mast, simply because that is where the front person sits - the back rest of the front seat leans pretty much directly against the wooden mast foot that we have built, and which is ratchet strapped to the boat (we did not want to drill any holes into the boat that weren't already there, and have succeeded in that so far).

We may or may not add a jib of some description later on; but if we do, are likely not to use it (often) when sailing the boat with two people in it (which is nearly always), simply because it probably gets in the way of the front person too much. So we need to maximize the propulsion that we can get out of our main sail, while still keeping things as simple to make and to use as possible.

The relatively long leeboards swivel and thus allow to adjust the centre of lateral resistance fore and aft to some extent, which should help to balance the boat, and allows for some flexibility with the exact shape of the main sail. We have positioned the leeboards with sailing with only the main sail in mind.

As you can see, we have devised a rudder control system that allows the rudder to be controlled from either the rear or the front seat, and by either hand or foot. We are also intending to make the running rigging accessible from either seat. The idea behind this is flexibility - either of us will be able to control the entire boat, for example if the other person is fishing, navigating, or whatever else. It also allows my son to stop the boat (reef) and to either sail or paddle it back to me should I ever fall over board unintentionally. And if one of us should get injured, the other one can still sail the boat, regardless which seat each of us is sitting in.

So... that's as much as I can think of telling you right now. Maybe more information than you need to know, but I thought some background of what we're trying to achieve may be useful, and potentially interesting for some.

My question is simply: What are your thoughts on the design of the sail? Which of my thoughts make sense, which don't in your opinion, what suggestions do you have?

I would hugely appreciate if you can share any ideas that you may have, so that we can soon add wind power to our coastal adventures - down here in New Zealand, it's summer right now!

Thank you for reading, looking forward to hear what others think!

Cheers,

Richy