Posts here span over ten years; newest last.
WindPaddle went bust but Anfibio make something similar.
Page updated Summer 2022

• To see how I made a disc sail click this
• This is how it worked first time out in a packraft
• This is how it worked first time out in my Incept kayak
• Pacific Action ‘V’ sail fitted on my K40
• Pacific Action sailing in strong winds in Western Australia. There’s a video too
• A knock-off ‘Windpaddle – fun while it lasted
• Ditching the cheap disc sail and getting a Windpaddle Adventure II
• WindPaddle Adventure II sail on my Seawave
• MRS Nomad packraft with WindPaddle II
• More WindPaddling with the Seawave
• Tested: Anfibio packrafting AirSail
• WindPaddling in Scotland with Seawave
• Packraft sailing in Knoydart (MRS Nomad, Anfibio Rebel 2K)
• Sailing struggles with Anfibio TXL
• Sailing sorted on Anfibio TXL
  

You may have read in the Shark Bay story what a relief it was to turn into the wind at Cape Peron (Western Australia), get Jeff to flick up his Pacific Action sail (below left) and shoot down across Hopeless Reach, with me clinging to Jeff’s hefty sea kayak. There’s a bit more Pacific Action sailing action attached to an Incept K40 in this video.
To me, sailing a kayak or packraft is a smart idea in the right conditions and with kayaks, some people think so too. I remember years ago the old US-dominated packraft forum didn’t get so excited when a bloke demo’d a WindPaddle on his packraft; perhaps back then most North American packrafters did rivers, not lakes or certainly not sea. In Scotland where the lochs can be long wind-channels and the boggy ground alongside horrible to walk over with a full pack, sailing a packraft down a 20-km valley full of water with little effort makes sense.

V-sails and Umbrella sailing
I never got round to fitting am Australian Pacific Action sail [left] onto the Sunny IK. In the UK they cost around £250 but it’s more or less two sticks, a sheet plus some string. Here is a great thread on SotP about making your own V-sail. I’m not sure they sell them in the UK at the moment.
I read about a guy who mentioned he umbrella-sailed his packraft back across an Arizona lake on an afternoon breeze. So with an old brolly I’ve barely used in 20 years, I gave it a go.

First time was in the Sunny kayak on a very windy day – too windy in fact. I found an out-of-the-way loch, hacked into the 20-mph headwind, turned round and opened up the umbrella expecting to catch the wind and rip back to the shore like an ekranoplan. No such luck. In a way the good thing with a brolly is that it inverts long before it drags you out of the boat and across the lake like a character from a cartoon. But because of that in-built safety overload, I couldn’t get going. Oddly, all that happened was instead of the bow coming round downwind, the boat kept getting side-on until the brolly inverting on a gust – a problem I found with my TXL packraft ten years later.

A few days later I tried with my much lighter Denali Llama packraft (above left), but this rare day there was not enough wind to prove anything. As you can see left, I tried to use the paddle as a rudder to hold the stern in line, but on that day it would have been better used in its traditional role.

Flip-out Disc Sails (WindPaddle, etc)
Then disc sails came to my attention: lighter, simpler and more compact than a PA. They work like those clever flip-out tents (see below): release a sling and it springs into shape on an unfurling hoop or batten.

French gonflard, Andypink (blog since deleted) designed a 1.2m2 ‘spoon sail‘ which was sold by Bic (now called TaheSport) for under half the price of a smaller US-made WindPaddle (good canoer’s review here). But these are no longer made, as far as I can see.
After making myself an ultra-basic home-made version from a spare tent, I’d say the Bic differs in the following ways:

• It has a window – always nice to see what’s ahead.
• I assumed the inverted teardrop shape would make it unstable, but like a PA, it’s bigger up top where there’s significantly more wind.
• The ‘control string’ attaches to the side of the sail at three points and then is attached to the hull (not one point and held in the hand like my MYO disc). I presume they are all chosen in position and length to maintain an optimal form. 
• It seems the dishing as featured on a WindPaddle and its knock-offs is not necessary.

Here’s a good intro to kayak sailing on Douglas Wilcox’s inspiring Scottish sea kayaking blog. DW paddles hardshells mostly, has actual sailboat experience and these days uses a fixed Flat Earth sail (a jib?) which I don’t think would work on an IK, far less a packraft.
Douglas told me that on the faster boats they all use (proper sea kayaks with bows sharp enough to cut week-old brie) the WindPaddle proved to have a fairly narrow range of operational effectiveness (same with the Bic I imagine). In a strong wind the flexible hoop distorts and loses effectiveness; and in a light wind they find it’s barely worth the bother. But don’t forget this is in a slick kayak that can easily be paddled at 8kph through the swell. A packraft manages about half that and fast IK like a Seawave or Incept maybe 70-80% of that speed. So at the lower wind speeds I can paddle, a sail is worthwhile – and in sail-distorting high winds; well, it didn’t happen with mine in 20mph winds (F4-5). I didn’t go that fast, but I can’t see me voluntarily being out at sea at wind speeds of 30mph, which is F6. It’s F7 out the window right now, pelting down and the sea looks utterly grim.

A ‘0.9m2’ WindPaddle is the same size as my disc sail, left (ie: 1m diametre which = a radius of 0.5m x 0.5m x π actually = 0.785 m2, but perhaps the dishing makes a bigger area?). As this guy suggested, this may not represent great value for money for a nylon sheet in a hoop plus some string. My own disc sail seems to work OK, but I may end up trying a Pacific Action – see below. My only reservations might be that it’s yet more stuff and a PA will be a little more complicated to rig and operate than a plain old disc sail.

Home-made disc sail
I forget of course that my disc sail was primarily made as a portable sail for my packraft; I never really expected it to work on my Incept IK, but having done so anyway, I think at 0.78m2 it’s too small and too low. I block much of the backwind and the higher a sail the better it works.

We were out yesterday on Loch Broom with Steve and Micheal in the Feathercrafts and me in the K40. By the time we finally put in at the back of the loch near the river, it had gotten windy and the fetch up the valley was pushing up a short chop which mid-loch, made forward progress slow. But now I have a nifty way of carrying my disc sail securely and out of the way on the Incept, I deployed it for the return. 
As before, I found a stiff headwind paddled into at 5kph (graph, left), didn’t correspond into a scintillating downwind glide under sail. Top speed was just over 10kph at which point things begin to get interesting and you want more. But most of the time Steve was able to keep up and even take pictures between paddling his Kahuna, so all I was gaining was some rest rather than extra speed.

Nothing wrong with resting on the move, but compact and handy though it is, I think my home-made disc sail is too small to get the K40 moving, let alone adding a camping payload. Researching more about V-sails, including the SotP thread mentioned above, I see in the UK PA sails were getting discounted to nearly the same price as a WindPaddle.

Having thought it over and actually seen one in use, a PA is more like the real thing compared to any disc sail, whose USP is that they’re compact and deploy in a flash. What a WindPaddle or my home-made disc sail can’t do so easily on the water in anything longer than a packraft is fold right up easily.
But alone on a choppy sea in a long kayak, it’s far out of reach on the bow of my Incept, unless I just pull it back and lash it down over my knees. A headwind would hold it in place like that, but one may have other things on one’s mind in heavy conditions and a side- or back-wind gust could catch it where it might dig into the water and act as an unwanted sea anchor, upsetting the boat. We don’t want that either.

So, having experimented with the concept of kayak sailing for little outlay, I can now see the value in actually buying something like a PA, partly because we’re heading for Ningaloo this September where a sail will be useful, and sail-savvy Jeff will be there to give me some tuition in the art. Short version: it didn’t go so well for me.

WindPaddle 2
For the last few years I’ve settled on a 1.2-metre ø WindPaddle 2 Adventure sail. Prices dropped to around just before they stopped trading and you can see it’s worth paying for a composite batten (hoop) which won’t snap after a couple of weeks. On my Seawave it worked, but I decided the old problem of weathercocking (back end getting blown round) was down to a too small skeg or too short rudder. I fixed that with a long rudder on a Sussex coast paddle.

With packrafts the big revelation was finding a quick way to fold it in half and tuck under a bow bag – and pull it out just as fast. As long as your skeg is fully submerged (on my Anfibio TXL I moved it forward to the floor), the boat sails straight provided wave crests don’t lift the back up for too long.