A Matter of Size
Updated: Nov 5, 2019
Foils have taken off and are definitely here to stay. We have a huge range available at SurfDoctor to get you foiling and a team ready to answer all your questions. If you are new to windfoiling and need help to guide you through the plethora of choice, we are here for you and we will get you flying in no time! If you are already loyal to the foil we also have shiny new foils to tempt you and take your foiling to a higher plane!
Pretty much every brand has a selection of foils to choose from; Starboard alone have seven different windsurf foil setups in their 2020 line-up. Joining some of the familiar windsurf and kitesurf brands, we have companies entering the foil market from other fields, such as the surf industry and even highly-specialist composite production backgrounds.
Windsurfing and foiling is not new; in fact Maui legend and windsurfing pioneer Rush Randall was windfoiling two decades ago! But in recent years, we have witnessed a lot more development in foils, in terms of design, technology and production, making them both cheaper and more accessible. There has certainly been a big push from all water-based sports, focussing on their own personal development direction of foils. Dinghy sailors, multihull brands, keelboat and yacht companies, kiters, surfers and paddle-boarders have all invested a lot of time, money and energy in making their foils more efficient, more performance-oriented ... or even just more practical. A whole new facet of the watersport world is emerging as a result, with cross-pollination occurring between the respective backgrounds.
And whilst many foils are still built with a specific sport in mind, there are an ever-growing number available that can crossover or traverse sports. With many companies making so many different foils, it can be a bit of a minefield deciding which one will suit you. So to help you understand the characteristics of a foil, we'll aim to decipher some of the terminology used in the foiling world here. And in doing so, you will then have an idea of the foil's purpose, just by looking at it and knowing its dimensions.
Just like an aeroplane wing using air to create lift and take off, a foil works by using our forward momentum, making water pass over our foil and creating that same lift. As the board picks up speed over the water, the foil will create more lift, we can then change the angle of the foil by using our weight to get the board to release from the water. Once the board is up and foiling we need to level out the foil to maintain our foiling height. As we start to slow down the foil creates less lift. As we slow down even more, we will find that our combined weight with our kit will be too much for the foil, and gravity will bring us back down. This is our foil stalling. So the two important speed values we need to concern ourselves with are our take off speed and our stall speed.
The larger surface area foils will have a lower take off speed and also a lower stall speed. This gives them the ability to get going and keep going in lighter winds. Foils with the lower surface area will need more speed to get up and foiling, but as they have less surface area they also have less drag and therefore a higher speed.
A common question asked of us in the centre is, "What sort of foil should I get?" and there is definitely no answer to exclusively satisfy everyone. Budget aside, probably the easiest way to help choose initially is to try and match the foil type up with the kit that you already use. So if you have freeride kit, go for a freeride foil; this means that everything will match and probably work quite well together. If you are a frothing, adrenaline-fuelled slalom sailor or racer, then maybe not choosing a full race foil to start out on ... but maybe something that you could upgrade to a racier spec as you progress. The other side to this is that you will then end up with a foil that you will enjoy long term and that matches your sailing style; not something you will feel you need to change once you've learnt the basics.
The foils between 1000 & 1500cm² mark that we are seeing people use are giving newbies to foiling huge success. Even on their first ever flights and after not a huge amount of time, they are foiling into and around gybes. People look at these big foils as training wheels before they move onto a smaller faster setups, but actually the the big wings are great all-rounders. If you are into general blasting and freeriding then they will probably suit you down to a tee. Their size gives you the stability for learning the manoeuvres and they aren't actually that slow. The Slingshot Infinity 76 has an overall size of 1534cm² and an advertised top speed of 26mph, which isn't too dissimilar to regular big kit blasting speeds, but with the added bonus that you can go down a few sail sizes. Wings that are around 1500cm² and bigger are good crossover foils (some more so than others). This bigger size is what you need to be able to do some surf foiling, wake-foiling, SUP foiling and also the latest water sport: wingfoiling. It also makes for a super cruisy kite-foil too. So if you're into spending time on the water, having a foil that can cover multiple sports would suit you.
When foils around the 1500cm² started hitting the market less than two years ago, they looked out of place. Now we are seeing up to two and a half thousand square centimetre foils from some of the major brands. These may not be directly aimed at windsurfers, but they will work and have the potential to get you up and foiling in under 10 knots, meaning that there is a potential for a lot more time on the water.