A foil to catch the fast but not yet powerful swell far from the shore?

Prone Surf Foiling
1

Hello,

I am trying to solve an equation, finding a foil that both lifts on low power swell, and is fast.
Does it exist?

Background:

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1- distant swell, fast, not powerful
2- near swell, slower, more powerful (curving)
3- wave

Using my daily driver Code 980s, my playground is mostly between #2 and #3.

My spot mostly works at high tide.
The swell progressively curves hundreds of meters before breaking into a wave.
The distance between #2 and #3 is good.

At low tide, the swell is weak all the way long, and then brutally curves and breaks into a tube on shallow water (1 to 1.5meter).
The #2 barely exists, or we could say that the distance between #2 and #3 is very small.

EDIT: Actual video of my spot, low tide then high tide.
Same day, same conditions (1.2m - 10s)

My objective is to extend the ride by taking the swell at position #1 !

So the other day at Low tide, I decided to try to catch the swell at #1 using Foildrive and my Code 980s.
I can get on foil and catch the swell for a few seconds.
But it does not carry me.
The swell is too fast and overtake me.
Pumping aggressively extends a bit the ride, but not much.

I need another foil.
Intuitively I would say a larger foil, because it would better capture the low energy from the swell at #1.
But this swell at #1 is also very fast, not yet slowed down by the bottom of the ocean.

So what kind of foil would I need?
A large CodeR or Axis Fireball would work ?
With small stab I guess.

Cheers

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Smaller foil will move faster with less drag. The drag of the 980s is making the wave outpace you. Using a smaller foil with less drag will allow you to stay with the wave from spot 1. Try a 720s.

Alternative. Use the same foil youā€™re on. Ride super duper high on the mast which will eliminate mast drag. Once you get it to speed and can ride that high, it should be fine.

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Ditto to this.

The 720s should be a better choice.

Ride really high on the mast and allow yourself to slowly ride lower on the mast to keep speed. Then reset the height and repeat. .

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My first advise would be to foil in prone on the 980S at #3 and pump out to #2 and #1. If that didnā€™t work, then get a Foil Drive. Iā€™m used to Pacific Ocean long period swell (14-20sec) that once standing on foil, itā€™s very easy to go fast as the long period (fast moving swell) gives a lot of push. So the challenge is to ride the smallest and fastest foil and one that wonā€™t eject you when you reach point #3.

Your handle is ā€œMediteraneanā€ and you state not powerful, so I bet your period is more like 6-10 seconds which is a slow wave. Slow waves require more height for the same push, as with that height you can make s turns to gain speed. If you donā€™t have the height, and a slow wave, and you canā€™t generate enough speed from turning technique, then you need a bigger and slower foil that will catch the limited enery you haveā€¦ I would think the 980S which has insane glide and turns great combined with your FD to get moving would be the ticket. The 1130S is noticeably slower, but still turns ok, so if you like to stand tall and cruise, should work fine and keep you moving with the ground swell until you reach the wave.

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If you want to foil on #1 style waves then you need the R. I basically only tow foil condition like #1. heres the 860r https://photos.app.goo.gl/YdVffLfoVZk2GMs38

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I might have missed it, but I think the answer is get a nice long downwind board and paddle it up. You can catch anything if you can flatwater start. Even a tiny bit of fast moving swell is infinately easier than getting up in flatwater. Timing is key. you need to start paddling like a flatwater start a bit early, and the fast moving swell comes and picks you up when youā€™re already almost out of the water.

I havenā€™t found a code 980S too slow to go straight on unbreaking long period open ocean swell. Its too slow to cut at an angle or make turns though until the wave slows down and steepens up

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I think @mediterranean_foiler is now on the French Atlantic side, which is known for itā€™s very deep to very shallow big energy barrels. Which I think is going to be a problem for this plan, as the transition is fast and aggressive, and the period is quite long I would guess?

Iā€™ve found that even my fastest foils struggle to keep up until the swell energy starts finding the sea floor, and then they donā€™t take long to start breaking. So itā€™s often a dance.

Very much depends on finding the right sea floor that starts slowing down but doesnā€™t break

The best you can hope for is this type of this from @spark

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I am indeed on the Atlantic coast, conditions are usually around 1m / 10sec period.
At low tide it gets aggressively hollow, thatā€™s why I want to ride the more distant swell which is weak.

Thanks all others for your suggestions.
Itā€™s counterintuitive for me that I should go smaller in foil size to catch the more distant weaker swell.
I guess smaller and Code R series would work (more glide).

@Meow yes these conditions look like what Iā€™m getting ~200 meters from the shore.

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I think @mediterranean_foiler is now on the French Atlantic side, which is known for itā€™s very deep to very shallow big energy barrels. Which I think is going to be a problem for this plan, as the transition is fast and aggressive, and the period is quite long I would guess?

If that ā€˜s the case, then Meow might be correct, use an 860R and ride the swell more parallel to the beach. But that doesnā€™t sound like the conditions described. Mediteranean foiler should take a picture of the actual spot and provide swell readings, otherwise itā€™s all just a waste of our time. And Iā€™m supposed to be working right nowā€¦!

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Let me try to clarify.
The description that Matt gave is correct.
The image I posted is an illustration, but it looks like my spot (at high tide).
At low tide, the distance between 2 and 3 is smaller, the soft swell abruptly turns into into a curly wave.
This is an actual pic of a nearby spot (Seignose), likely at low tide (on a big day).
As you can see, beyond the peak, itā€™s pretty calm, thereā€™s not much to rideā€¦ but there is somethingā€¦small, fast.

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sure, but waves start interacting with the sea floor at quite deep depths usually pretty far out if it is a good surf spot. You can look up the term ā€œShoalingā€. Theyā€™ve already slowed down and consolidated from raw ocean swell to organized waves by the time they look like the images posted. Iā€™m doing exactly what the original poster wants to do with a nice long SUP and often with big foils, but not always. Size of the foil seems to correlate to BOTH speed of the wave (period) and size/steepness.

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3ft at 10sec to us Pacific Ocean folk is Spring windswell and not rideable due to onshore winds. The vid from Spark on the 810x is probably 10ft @ 14sec and has wrapped aabout 90 deg around a huge headland slowing the wave a lot. Seignose is an epic surf spot and when on, is probably 2m @ 12sec (7ft) So my point is that you need to match the speed of the wave and what you plan on doing with it. A big day stay way outside and run downwinders, a small day, find an outerbank and try to work the wave. If the swell doesnā€™t carry you, a Code 860R will lift about the same as the 980S but glide on a bit less energy. A Code 1130S would be like your 980s with a bit more forgiveness from dropping out, but not a lot more carry (glide.) Maybe go up to a 1300S? In general, if you canā€™t stay with ground swell, you need a more downwind R type of foil, but for small short period waves, youā€™ll want a big S type foil! Sounds like you need to do some experimenting!

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FYI, hereā€™s a video of Ocean Beach which is our Seignose, at I would guess 3-5ā€™ (1-1.5m) @ 12-14 sec. The rider J. Heineken is world class riding a 90?cm mast and smallish Mikeā€™s Lab foil. Heā€™s the only person Iā€™ve seen make this spot look good. And a guy on a fully motorized E-foil who stays way outside. Some breaks are best left not foiled! On the other hand (East Coast) they get lots of epic 1m @ 10 second beach break that runs down the coast and you can ride tiny barreling waves in glassy conditions.

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Man this whole thread is like a tour of my own personal foiling hell! TBH 10 secs is a bit much, 8 secs is good and 6 is (chefs kiss). If I had to look at waves this pretty but this impossible to foil it MIGHT even be enough to drive me to SURFING

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If Seignose is like that Ocean Beach video, thatā€™s this past summer on Oahu. I didnā€™t enjoy those conditions until I demoed the 720s and 810x. Everything else was just too much escalating lift and locked in under that much power. I started to really enjoy those days with a smaller foil.

I donā€™t actually find the top speeds of the R wings any faster than the S. I think the 720S should be plenty to catch your #1 swells, but you gotta keep hanging turns to create speed. If youā€™re the type to just cruise straight IDK if itā€™ll be as effective. Itā€™s actually something I really liked about the smaller span wings, you had all these opportunities to generate speed and lift because you can turn easier than the big wings. Also fast shifts in wave shape were so much easier to adapt to because the wings are nimble.

For reference, most of the time I have to pump more like from #3 to #1 to connect due to inconsistency, so I went with the 850s. After getting used to the 720s though I found all the extra lift unnecessary, so I shimmed some of the lift out of my tail. Have to deal with breaching a little more often, but I traded like 10% of my turning for a 50% increase in pump. Top speed is similar. When in doubt the 850s can prob do the job (in nearly all conditions).

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Also, Iā€™d recommend a good mid-length to paddle in as early as possible. It makes those days so much more fun for me. I typically sit with the longboarders.

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I too find longer period, low amplitude waves (sans significant bottom effects to slow down and steepen up the wave) challenging both with respect to gear and technique because they demand so much efficiency.

The technique side has been covered a bit above with staying high on the mast. Turns, if even possible, need to be very drawn out and you have to stay in the peak power part of the wave face. This zone is actually kinda big on a long period, low steepness, wave face but because of the speed it and you are moving at, my experience is that there is actually less margin for drifting outside of the power zone than on a wave that is standing up more.

On the foil side, high aspect ratio to minimize lift induced drag and foil sections that are working at a very high lift to drag ratio at the operating point you are at on the wave (weight all up, speed) are essential to getting the efficiency needed. Aspect ratio here is mostly pretty straight forward in this scenario - more is better.

A 10s open water wave has a wave speed (celerity) of about 56km/h, which is a 1 minute and 4 second kilometer. Getting to a high lift/drag ratio operating point at this kind of very high speed breaks down into two main categories, that I can think of:

  1. A fairly typical foil section, operating at the optimal angle of attack for lift/drag ratio. I havenā€™t seen any data or analysis for the latest crop of fairly cambered foils, but if it is anything like what I am familiar with from the published literature, this angle of attack is at least 5 degrees, often more. Getting a foil to operate at 5 degrees AoA at 56km/h means it must be tiny. Teeny tiny. Which is where the advice for going to a smaller foil is likely coming from. Starting a foil this small without a chip in will be very hard, even with a FD. On the up side, if you can get on the wave this foil will likely feel reasonably manageable as you bomb down the face.
  2. A foil with incredible top end operating at very low angles of attack due to the high speed, in fact trending towards the zero lift angle of attack. This means zero lift drag for the section is the key consideration. Camber and thickness are two main parameters that increase zero lift drag and thus limit top end. So, damn near a symmetrical foil that is super thin is ideal here. Going to be hard to ride due to the aggressive stall characterics and super twitchy on the wave because it will probably be running at 1 degree AoA or so (making a 0.25 degree pitch change a 25% change in lift).

Finally, FD tips for trying to get to the very high launch speed needed. At 95-100kg suited and wet, the limiting factor for top speed for me is ventilation on the propeller due to the cable running down the back of the mast. The 3 blade propeller deals with this better and gives me a better top end at my weight, but does reduce maximum propeller RPM so may not yield the same result for a lighter rider, or someone on a FD integrated mast. Getting the propeller further under water helps this, I have the 25cm cable and after much playing around if I want to catch fast, low amplitude swell I have to run it at maximum depth and keep the board close to the water. Naturally, running low like this increased wetted surface on the mast so a 75cm mast instead of my 85cm would give me another big boost in top end.

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what tail are you on and how much shim ?

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Hello all,
Thanks for the great answers!
It wonā€™t add much to the conversation, but FYI Iā€™ve recorded the typical conditions I get.

The video shows 2 clips 4 hours apart: low tide, then high tide.
Stable condition, 1.2m waves, 10s period, low cross off wind.

Low tide, chill at the back, barely any visible swell, then mini tube forming out of nowhere on 1m of water.

High tide much more progressive and mellow breaks.

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Yes these are much the same as my conditions, we just get more tide, but the low tide small and rapidly deep to shallow makes for tough foiling. I usually find myself on something like bottom left of your low tide clip, or surfing once the tide pushes in and there is a reform.

My experience in similar setups (deep then shallow) is that the waves donā€™t slow down enough, and then they suddenly break. This is riding AFS 750 Ultra dw foil (equivalent to Code 770R), and Silk 850 (similar to 810x), both of which can go fast enough, but that is going mostly straight, and then kickout as it breaks.

The problem becomes you can only go straight. Not that fun. The key is finding sandbanks where you have waves breaking and then backing off, or a deep channel.

Agree with these points, but smaller is usually faster which is important

I have a nice library of related books on the topic.