In this blog I will elaborate on the differences between the Flat Earth sail and the Falcon sail. Roughly speaking, Flat Earth is very forgiving and therefore a little slow, but suitable for every paddlesailor in strong wind, up to force 6, if necessary, on large water with waves of roughly one and a half meters. Falcon is faster in all winds, so great for recreational paddlesailors who want a relaxed day out sailing. But in force 5 to 6, the Falcon is a lightning-fast Arabian thoroughbred. Exciting for experienced paddle sailors who need a kick, less recommended for beginners due to the greater heeling forces on a beam course. So it is wise to look honestly into the mirror and ask yourself what kind of paddler you are before making a choice.
To get an idea here's a YouTube video of Patrick Forrester, the owner of Falcon Sails. Looks like a downwind force 4 or 5.. The wind seems to blow not as hard, but his own forward speed gives the optical illusion of calm waters. Now and then he shoots sideways to half wind to keep an eye on his fellow sailors. Wow… Is that something for you or rather not?
Here's the Flat Earth sail in even a stiffer wind and a little more tricky course on close reaching since the heeling force increases even more. Nevertheless the kayak stays upright, thanks to the sail and the seasoned kayaker. Now that's typical for a Flat Earth sail: relatively smooth paddlesailing in harsh conditions but also not quite as giddy and fast as a Falcon sail.
And here's an example of my own Falcon sail in a super light breeze of force 2 or three. Despite the lack of wind, I make a decent speed already. This would not be the case with a Flat Earth sail. I would've had to make a couple of extra paddlestrokes.
Let's take a look at the differences in the design of the two sails to understand and appreciate the different performances.
Twist
An important characteristic of a good sail is the degree of twist, or spiral shape. A sail is not a flat piece of cloth, but is slightly twisted. The lowest part of the sail along the boom is not as far out as the top of the sail. This creates a certain spiral shape in the sail. This happens in part by itself because only the bottom with the boom is attached to the sheet, while the top of the sail hangs loose and can therefore turn a little away from the wind. For another part, sailmakers cut the lines of the sewn together sailpanels in such a way that extra twist is added. But why is that spiral shape necessary?
Unfortunately, sailors do not have to deal with just one wind direction. At first glance they do. For example, if you are sailing at a beam course with the wind coming in perpendiculair, the wind will be perpendicular to the boat. That is simple. But yes, the boat itself also moves forward. This has a significant effect on the angle of the wind hitting your boat. Suppose you have a wind vane at the top. It will flutter exactly 90 degrees outward when the kayak is stationary. But as the boat picks up speed, the vane will also move a little backward. From the sailors point of view the wind suddenly seems to be coming a little from the front when he looks at the vane or feels the wind on his face. We call this false image the 'apparent wind'. The actual wind, of course, still comes from the far left or right.
The problem with this is that the beam wind usually blows harder at the top of the sail than at the bottom, where the waves often disturb the wind a bit. The effect of your own forward speed is therefore less at the top, because the hard, unhindered beam wind still predominates there. Down below the effect of the forward speed is somewhat greater because the wind cannot blow freely there. So in your cockpit the wind seems to shift forward as you move along. More than at the top. So .... the sail at the bottom should also be sheeted in a bit more - as if you were paddlesailing a bit upwind. The top stays loose because the true, unblocked wind is still perpendiculair to the kayak And voilá, there is the need for a sail with the right twist to adjust the sail to the two different windangles
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| An almost 150 years old Dutch tjalk with a raised stern. The boom is sheeted in tight while the gaff top swirls out quite a bit, resulting in a clearly visible twist. Photo: Molenaar Sailmakers |
Twist is also important for kayak sails, although the difference in wind direction above and below is much smaller. But there's another important reason for twist in a kayaksail. Due to the spiral in the sail some of the wind will turn upwards and disappear over the top. This is called windspill which is very pleasant in strong winds. Thanks to the twist, the heeling force can be limited.
Flat Earth has based its entire corporate philosophy on this idea. A Flat Earth sail, originally developed on the rough Tasman Sea off Australia, is ideally suited for strong winds. Most of the wind flies up by itself and is then gone. The first models had a lot of twist, later on it was reduced to normal proportions. I believe that the Falcon sail has a little less spiraling-off effect. The sail is a standard triangle with the top fairly close to the mast as opposed to a Flat Earth with battens that keep the sail at the top much further back and therefor easier to turn away from the wind.
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| An old model Flat Earth sail with a mindblowing twist of 21 degrees difference between the top and the boom. The wind is released quckly. |
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A newer model Flat Earth with only 12 degrees twist. It holds on to the wind a bit more.
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Another notable difference between Flat Earth and Falcon is that the Flat Earth sail has an even curvature when viewed from above. It seems as if the makers have come up with a circle and have taken a piece from it.
Falcon is much more like an airplane wing (see 'Sailing for dummies'). The deepest point or camber is mainly directly behind the mast and then flares out slightly to the rear. This creates a suction behind the sail that greatly aids in the forward drive. Almost all sails in the world have that aircraft profile.
Now you may understand the basic philosophy of Falcon Sails. This sail is choosen for power (and quality). Flat Earth has choosen for simplicity and ease of use for beginners. The even curvature in the Flat Earth sail is almost automatically created by the sewn-in flexible sprit that holds out the top of the sail. This keeps the sail low with less heeling force, while still providing a reasonable square surface. The result of a sewn-in batten however, is that the aircraft wing shape is difficult to accomplish. A Flat Earth sail has probably considerably less suction at the back side, I suspect. This also helps in limiting the heeling force. Very nice in strong winds, but less advantageous in lighter winds.
Rig and price
The rig of the two sails differ quite a bit but the quality is comparible so I don't want to go into this. You should neither. The key question is wether you want speed and/or stability in rough winds.
The two sails do not differ much in price. A complete set of Falcon (1 square meter sail plus all accessories) costs $ 545 A slightly larger 1.4 square meter sail with larger rig: $ 575 A separate sail costs $ 145 The larger sail $ 175 - There also seems to be a smaller Falcon sail of 0.7 square meters.
In my experience it is possible to make your own rig, but not cheaper. And designing and sewing a sail yourself is just as expensive as ordering one, but it is fun to do if you don't dread a lot of work. See my blog 'Make your own sail' for this. As a beginner, I wouldn't venture into it and just buy a sail with the rigging. See also www.falconsails.com
A Flat Earth type Trade Wind of 0.8 square meters complete with accessories costs 500 euros, via importer for the Netherlands Axel Schoevers (www.zeekajak.nl). The sails come from England, so hurry up with ordering because the price could go up after Brexit settles down.
Both suppliers may be susceptible to a quatum discount if, for example, ten people of a kayakclub order a sail in one deal.
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