WHAT ARE THEY, HOW DO THEY WORK AND WHAT SIZE SHOULD I BE LOOKING FOR?
Armie Armstrong, guru behind Armstrong foils, takes over the keyboard for this section to give you a brief overview of how foils work, what to look for... and who was riding them first!
WINGS UNDER WATER Hydrofoils are very simply wings in water. Although, evidence of hydrofoil use extends right back to the dawn of the 20th century, the modern surf and kite foil set-ups all basically stem from the original sit-down hydrofoil system developed in the late eighties, by American Mike Murphy and his waterski buddies. Mike is a living legend who still rips on foils in his 70s! He made Laird Hamilton’s first foil set-up and the rest is history.
Here’s a video of Mike from 2014, chewing the waterski foiling cud. Things have moved on considerably even in just six years since then, but it’s interesting to understand more about foiling heritage from Mike all the same.
And just for hoots, here’s another (BTW you don’t need a mast this long!)
The fundamentals of this original, single, vertical (mast) and two wing, T-Bar (mast & fuselage) foil system have not really changed. The front foil wing delivers the lift and most of the drag characteristics, while the rear foil wing (stabiliser / tail) sets the pitch stability and helps with yaw control; basically determining directional stability for the ride. Stabiliser size and pitch are critical in all foil set ups. The bigger the wing and greater downwards angle / force adds stability at lower speeds, while a smaller wing with less angle (or even a slightly positive angle) allows faster and more reactive riding with a more forward foil geometry.
“A bigger, thicker, front foil wing will have more lifting power and be more stable at low speeds, while a thinner, finer foil will have more top end speed range, but less lift and control at low speeds. Be realistic about your level and choose what will see you having the most fun and progressing easily.”
There are at least 20 main parameters that go into the fundamentals of foil system design, with elements like section shape, chord percentage, thickness, plan-form, aspect ratio, anhedral tip curve and form drag etc. etc. – all combining to deliver a foil set-up’s unique ride characteristics. There is always a trade-off between these parameters, but the fun part is putting them all together; to deliver the sublime, fluid sensation that foiling gives riders who persevere beyond the initial learning phase.
WHAT YOU NEED FOR WING FOILING Let’s take a quick look at wing foiling and kite foiling, because if we go into all the variables of wake, surf, pump, windsurf etc. we will be here all day. So let’s firstly take a look at foils for winging and then I’ll run you through some differences with kite foils. For winging it’s best to start with a bigger, lower aspect, stable foil; something like our CF2400 that gets you flying at slow speed in moderate wind, allowing you to gain control of your board, foil and wing at a nice, slow pace. This will improve your progression speed, maximising riding time and reducing wipe-outs.
Something around 1850 or 1550cm² will be ideal for smaller riders once they’ve got the basic riding, transitions and wing handling sorted on the bigger foils. As you progress into stronger winds, smaller boards and faster speeds, all you have to do with a modular design is swap out the big front foil for a smaller, thinner option that delivers more top end performance. You will go faster and be able to achieve tighter turns and bigger jumps. My current favourite is our HS1050 in 20+ knots of wind – it’s so much fun riding with loads of wing power, going a lot faster, ripping waves and jumping higher.
The HS625 foil
The CF800 foil
The HS1850 foil
The CF2400 foil
KITING FOILS For kiting, you can use smaller foils and a shorter fuselage length because the lift from the kite provides lots of stability and drive. Essentially, the kite helps to hold you up. If you can already kitesurf, then learning to kite foil is probably the fastest and easiest way into the foiling world for you. I would recommend a modular design that has good wing foiling, surf or tow foil front wing options also available – so you could maximise your foiling fun in all conditions by simply adding a new front wing to your set-up.
For kiting, you’ll initially want something between 800 and 1,200cm² to get going. The theory is similar to winging: the larger foil gets you going at lower speeds in lighter wind, allowing more riding time to get your flying skills dialled and leading to quicker progress towards higher performance foiling. Generally a curvier foil is going to be more forgiving and have a surfier feel that is really fun to lean into turns and ride through wave turbulence. However, if you want to go racing above 30 knots, then you will need a super thin, straighter, higher-aspect foil like the new Levitaz Olympic race foil. Go for it, good luck and have fun!
How’s this for cross-over? Noah Flegel wake foiling on a low aspect CF1200 wing!
The cool thing about a stable lower aspect surf style foil se-tup is that you can then take it in the waves and have a blast when there is no wind. Check out Reo Stevens ripping on a CF800.