During the summer I got the chance of trying the hole range of the 3 battens concept sails from the 3.7 until the 5.0 and although at the beginning being quite aseptic my lack of confidence run out after trying it and got totally impressed.
This the main reason why I spent a lot of time sailing on them, not just limited to the Severne Sails, testing and comparing details with the other brands gives you a proper idea on what the concept is driven to and finally up to 6 different brands sailed on my hands.
I have to say that this sails are basically made for side or side off condition, for down the line wave were you want a good relese of the power and a good response after the top turn. On this cases the light weight of this sails is a fact that anybody can denny and makes the rig an extension of your body surfing, following the moves and delivering when its need.
The truth is that not on all the brands tested on the 3 battens concept I had the same feeling of an optimized sail. Easily you could see on some of the brands the lack of they test and development as you could feel on few others but I am happy to assure that the S.3 will deliver a very good sensation to the customer, allowing to enjoy one of the lightest and finest sail available for this 2015 season.
To be more specific there are few points to comment about the 3 battens sails:
Aspect Ratio (AR).
Different brands, different ideas. The are attempts on having both possibilities as an example the Hot Maui Sail KS3 which presents have the "S" bend de-power system but the S.3 have a constant shape that offers a moderate low power deliver on the bottom of the sail that keep pressure while the leach release on top turns or while jumping.
On the middle batten the AR is flatter compared to others though it keep front pressure once you ask for power on the luff. This characteristics give a lot of response to the sail specially on wave riding on a similar way the S.1 does. Both sails are considerate a down the line wave riding product though are not limited to it.
The lower batten above or under the boom.
Paying attention on most of the 3 battens sails and the development made until know trying to optimize them delivering a light and efficient product I see a general move to keep the lower batten under the boom. Until now I don't see any significant advantage on having it above, it would be supposed to give more stability on the release through the leach but in my experience it give a very stiff feeling on the models I used most of them prototypes as of all the brand I tried just one decided to keep it above.
Light weight and wider range of visibility.
This is the main point to work for a 3 battens concept. Having less battens gives more area for the plain panels and basically the central panel get the main responsibility to holds this, the biggest area. This is straight away and advantage on the visibility which is a big fact on the wave riding. On top of this it will offer a lighter version of any sail with more battens. Considering this sail a wave riding product another adavantadge to add on this models is how agile it feel on the bottom turn once you decide to low it and then pull it up until the top turn.
Big panels area and stability control.
As the panels got bigger most of the brands get a common point on using structural reforcements, as Severne does on other models, the Spiderfiber is the responsible of bring down all the sceptic sailors for apparent instability of the 3 battens. Is here, where on my opinion few brands failed this 2015 as well.
Bigger or smaller.
Apparently few big sailor had the chance to reduce the sail size though to the power delivery on certain brands thanks to the wide AR as the Ezzy Taka which deliver quite a lot of power. On the Severne S.3 a moderate caratcher its presure is delivered similar as a 4 or 5 battens sail. On the other hand as a light rider (75kg.) I can say that the S.3 have an exceptional release of power through the leach what allow me to use a bigger sail what means a bigger range for the model.