Boost Surfing FIN greatly inspired by Efoil

Hey cool…tell me more, did it work? EG enough forward momentum to get up on foil, then once out of the water minimal drag? Looking at this, I now realize one constraint: my mast will need to be longer.

The open prop kinda worries me a little though.

I am working on somthing similar! Here is concept 1, made several changes from this revision, but more or less the same.

There are a few very high discharge cells and I belive combining with a 6383 or 63100 outrunner you should be able to have it lift you all the way up!


Here is the current progress!
Currently printing the internal structures!

not very proud of the battery but I believe it will work.

Also here is the button I will be using to turn the thing on. It will be connected to an Arduino controlling the motor controller. One-click gives a boost of maybe 5 seconds or so. any suggestions of a durable wire that is easily tappable to the strut ideally OD of 4-5mm?

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For X-reference purpose, there were those projects from @drswitch:
'Submarine Build

and @Peter
'Peters Concept (Bavarian style)

talking to a foil buddy about my maybe-someday boost fin. He suggested it would be cool to pursue some kinda recharging system…eg while paddling back out, the prop spins, adding charge back to batteries. While I doubt that would do much for keeping up with power needs, it’s an interesting concept.

still waiting for my boost fin – aiming for assisted surf foil riding.

Some people posting on seabreeze forum about a similar but much heavier duty and more expensive version from Australia:

Seems kinda halfway to an efoil, aimed at downwind sup foiling.

$165 for a 3D printed mast clamp :rofl:

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Oof… $600 for a 6S 12A battery! At least throw a BMS in there. I wonder if he did anything to the motor or just grabbed it off the shelf. Actually if anyone knows How what covering he used for the phase cables and their connectors id really like to know.

I bet the creator is someone here… They probably grabbed the mast files from the mast section :rofl:

The easiest way to do the phase cables like that is to get a pipe/tube with a thin wall, then use a reinforced section (like a brass tube) for where the gland clamps over.


I bet you are right Jezza. And I think it may highlight an important business principle: it’s not about designing the better mousetrap, it’s about marketing it successfully.

I am obsessed with foiling, can’t get enough … but the tech threads on here are so intense, I can’t follow them, much less design my own motor assisted unit. So if someone is able to take the info users are sharing here and make something sellable, that’s a valuable service. Though personally I am too cheap to buy one. :slight_smile:

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Oh, brings some nice points:
1- a working plastic folding prop !
2- a Maytech remote control mount that adapts to paddle shafts or windfoil booms

In August 2019, I submitted the e-wingfoil idea. Happily, it was taken up and implemented. Long live who dared to reuse a Maytech remote control and who will surely replace it soon by a more adapted solution.


There’s a much less complicated and lighter way to get up wingfoiling in light wind. Use a big wing and pump the wing and foil like crazy! I’ve gotten up in 8 knts this way before and any less you can’t ride the wing anyway.

The real advantage in wing foiling would be figuring out how to get up on a really small board (20L) when its moderate wind, but I feel the best solution for that would be some kind of floatation device.

The battery box looks kind of nice anyone know where it is sourced from?
Would like to build a similar contraption.

It’s just a clear lid ip67 junction box with latches. Quite a lot of them online if you Google the right thing.

That is what I precisely want to avoid as it destroys your wing, this way wears it out prematurely.

It is also exhausting and at times only marginally successful. I figure just the slightest boost would help to break the water tension … once the board breaks the surface, you don’t need much wind to stay up.

But the goal for me is actually more about sup foiling … days when the waves are standing up but not quite breaking and you just barely can’t catch them. This could open up spots otherwise unrideable. Meaning: all the waves for me Me ME. :slight_smile:

and another, maybe halfway between the boost fin and foil drive, at $900ish.

Not even close to an e-foil of course, but would it have enough juice to get up on step to ride swell, wing, or pump from there?

240W is not enough, might help a bit in swell but in flat water you need between 2000 and 3000W to get on the foil (depending on weight, board volume and wing). I think everthing below 1000W is not a big help.