Epic project mate! I had great fun watching your build from the sidelines (aka our 3am fibre glassing session) and look forward to the next project!!

Very nice project indeed! Hope to see a next version of your design. As I build Hydrofoils myself (for kitesurfing mainly), here are some quick tips: The analogy with the stool with three legs isn't the best here, because the amount of struts/masts into the water is absolutely irrelevant for the foil to work. The principle is simple: its just a plane under water. The front wing produces lift to lift you out of the water while the rear wing produces downforce to compensate the "wheelie". The faster you go, the more lift the frontwing produces. As your foil has no elevators, the rearwing produces the needed downforce to keep the nose of the boat down, resulting in much less wheight adjustment that must be performed. This is the principle of kite/surf foils. For a boat, where your main focus is the ease of use and not so much the performance, a Fontwing in form of a V would be the best solution (extreme dihedral). The faster you get, the more the foil gets out of the water and isn't capable of producing lift (sadly, the so loved self stabilizing characteristic you get in planes with dihedral wings is almost neglectable due to the high center of gravity). With the dihedral frontwing, you can easyliy achieve solid results without a rear wing and without a long-shaft outboard. Just mount the foil further to the front (the position of your first approach seemed about right for that). The last tip: The Angle of attack is way more important than the profile. Even a flat surface will fly well. In water a thick profile will give you a lower lifting speed but drag of the wing induced by a bad designed profile will kill your topspeed and, much worse, the lift becomes enomous making ventilations more likely and the boat uncontrollable. Hope this wall of text helps a little for your next revision, subscribed :-*

My dad made a dinghy with a hydrofoil (as a prototype before making a 60-seater hydrofoil boat) back in the 1960's and took me out as a kid on it in Dartmouth harbour. I can still remember the moment when he put the foils (one on each side) down. We were going full speed already, but the acceleration at that moment was amazing! Doubled the speed in a couple of seconds and I suddenly understood what he had been telling me about how they worked. Sadly his business could never compete with the government-funded hovercraft industry, despite hydrofoils being so much more efficient (and comfortable) for routes like the cross-Channel ferry.

We need a bigger one! Use a polyester boat as base, and make a jack plate for the outboard so you can lower it :)

This was brilliant. You covered all of the bases of whether this could theoretically work! Well done.

Honestly suprised by the subscriber count, was expecting at least 10k.

I’ve been going to play around with this myself, except with a rigid bottom inflatable. I’m impressed they didn’t blow off earlier on! I’m an outboard mechanic by trade, so different motors, not so much of a challenge. I also have the advantage of living in a country with better Weather. You’ve given me a couple of different thoughts now.🤔💭 Thanks for sharing. 😎🏖🌴☀️🇦🇺

Can’t wait to see where your channel goes, this will give us something to watch while waiting for Tom to post another video :)

The flute made your maiden voyage so epic!

This looks great! Look forward to the next one

I'm glad i fast forwarded to the end.

I genuinely really enjoyed watching that! Brilliant video! Looking forward to the next one!

I've been wingfoiling and designing my own hydrofoils for a couple of years now. That front foil looked very thick to me. On the personal hydrofoils, weight placement on the foil board is absolutely critical. Also surfaces. The difference between a poorly finished surface and a 400 grit to 1000 grit finished surface with no imperfections is phenomenal. I 3D print my wings in sections with holes for joining dowels, fit them together and then spend a few days cleaning up the surface. Then I create moulds around them using parting tape and resin infusion. Finally I clean up the moulds and for my higher performance wings I make now, I fill them with carbon fibre, mostly unidirectional. Then I clamp my moulds together. Unmoulding, I clean up the excess with a mini angle grinder, then file and sandpaper in progressive finenesses. If you continue, you need to make a decision as to whether you are using self flattening foil designs for roll and how you will control pitch stability. And of course under an IRB, you will need a lot bigger foot glued or otherwise fastened to handle the forces. I really was surprised that the attachment you used lasted as long as it did.

Looking forward to more! Don't give up on this one!

I can't believe there's only 5k subs here... so this is what its like getting somewhere early.. 👌 250k+ this time next year?

Thumbs up for him , he is doing fiberglass in his kitchen. Fiberglass resin stinks and it won't go away

Great project Sam! Looking forward to the next one. 👍

Fun project! Get a copy of Ray Vellinga's Hydrofoils (Design, build, fly) book and try to understand it. Balancing pitch and roll stability to make a small hydrofoiling boat that will stay on its foils is quite difficult. Making your dinghy achieve manned flight (with a suitable engine, wings and prop) would actually be easier in some ways. Hydrofoils have all the lift vs. drag mathematics that aircraft have, but a few more because they have to also deal with the interactions between water and air at the surface and a big change of centre of gravity and stability when they take off. They also need turn stability if you want them to stay on foil when they reach a bend. The first foil you made was far too thick! If it was to get on foil, a foil that thick would be inefficient and therefore make the boat slower than with no foil at all. I built a hydrofoil when I was 15 (I'm now 47!). It worked a fair bit better than this, but I didn't have true pitch stability either. It was a series of multiple stalls like yours, just slightly longer ones. I had an angle of attack adjustment system for the front foils, but it was so hard to keep it flying for more than about 50ft at a time. I had beginners luck with mine, because since I have made a series of failed hydrofoils. I have learnt that, sadly, to make an effective working hydrofoil you need at least as much maths as you would need to design, from scratch, a working full sized aircraft. Hydrofoils are killers psychologically, because any kind of foil that creates lift, which anything vaguely foil shaped will provide, will enable a boat to lift and porpoise and stall and repeat. This makes the builder think that they are 'nearly there' with it, which they are not. There are rather a lot of 'nearly there' porpoising hydrofoils on youtube.

Fuxkin Brilliant... I love Ideas and I love innovations....

- You should use rapid prototyping to make a profile gauge and shape the foil in insulation foam. - The profile to use for that kind of speed and size is a Low Reynolds number Eppler profile E817. - To laminate fiberglass properly you can use cheap throw-away 1'' paint rollers. - You can only use epoxy to laminate fiberglass on the foam, polyester will melt it. You don't have to take my word for it but my final bachelor's degree as an engineer was designing hydrofoils for a boat and as an engineer, I've worked as a fiberglass mold shop foreman.

Great video and project!

Fun project. Hydrofoils are cool, but sometimes its hard to make them work, and depending on what boat they are mounted to, might be of questional benefit, if any at all. But it sure is fun building! One small correction: the effect you described is called "ventilation", not cavitation. An easy mistake to make, especially since the anti-ventilation plate mounted just above the prop on outboards is erroneously called "anti cavitation plate" in common parlance. But cavitation is a quite different phenomenon. Cheers.

Wow, looking forward to your next vid!

Sam, your humor alone is born for youtube. please keep making videos!

Looks great!

Love the endeavour, perseverance and courage. Just keep on trying Sam, 'cos you'll get there in the end.

Wow... Absolut nice project.. Hope to see more of it.. cheers.

Small point of note: Ventilation is when the prop sucks in air. Cavitation is when the prop is spinning faster than the water can move in around the blades and tiny pockets of vacuum form against the prop.

I really enjoyed your video! Keep it up! Looking forward to your next one.

Well done lads!

Great video look forward to seeing this channel sky rocket 🚀

I've been wanting to do this for ages but never got around to it. Good job!

Great project, can’t wait to see your next idea. Subscribed!

Hydrofoil airboat? Basically an aeroplane with its wings submerged. Or mounting (electric?) propellers on the rear hydrofoil, so they're guaranteed to be underwater.

Thanks for documenting, any failure is a success in terms of research.

I absolutely love this! I would have never considered just using fibreglass to make a part stronger thus you can utilize it in a practical application :0 Fantastic job

A freedee flyin’ boat

I love that the songs that he plays make it sound like your watching an add

inflatable dinghy is relatively heavy for what you're doing. I'm planning a similar project using a small lightweight trimaran hull and a jet drive. The idea is to have an intake under the bottom of the front foil and twin output nozzles under the back foil. The pump driven system will prime itself when it's sitting low in the water. Steerage will be done with both output nozzles using 360° rotating nozzles so it will have reverse and side thrust. The jet pumps will be powered by steam and the steam will be generated by a hybrid solar and alcohol boiler. The idea is to run it on sunlight during the day and alcohol or any volatile fluids I can scrounge or make at night. There's a conservation area near me where fossil fuel boats aren't allowed and I want to go speeding into it on a hydrofoil and get stopped by marine patrol so I can tell him that I'm not breaking the law but he is for following me into the area. 😂

6:26 Hard not to put a smile on your face lol

Looks nice

Totally something I have wanted to do for YEARS! FINALLY someone did it. But, please use Naca airfoils and loft. And also, you should think about making it self stabilizing.

An engineer pilot! Man you are someone who kids dream to become !

That’s a good start, don’t give up now!

From what I've heard you need to design the foils precisely so theyre stable and don't oscillate. Great attempt though!

Subbed! Great stuff.

Great video

Very entertaining, dont give up on it

outboard sucking air from the surface to the propeller is called ventilation. cavitation is empty air pocets created on the propeller under water through low pressure. great video hope to see some more

Brilliant story

Following. This could be a VERY COOL game changer for us small rib fans. KEEP GOING

They make long extension motors, often used for sail boats. this might keep the prop deeper.

Subscribed for the frequent and grammatically correct use of various forms of the word Bodge. :D

Just so ya know, carbon fiber fabric isn't as expensive as it once was. You can get it fairly cheaply, as well as carbon fiber rods online. Just get a bit of thin cardboard and glue several sheets of carbon fiber fabric to either side of it and you can trace and cut out any pattern your heart desires. Best part is, you don't have to wait days for it to be printed, and it's a lot more durable than any plastic. Also, is that your old motor sitting out in the rain at 9:10 😅

Nice video, this confirmed me the doubts I was having about building such a project myself with much more limited skills and tools... Nice work!

A 3d printed seaplane would be cool too

The right term is ventilation becouse cavitation is a vacuum bubble and ventilation is a ar bubble Nice vídeo 👌

Loved it. And have no doubt that you will make a successful project of this. Very good idea too - apart from a possible efficiency gain, if a choppy water ride could be smoothed out, this would be a massive win and very interesting.

Looks good - u gonna go big mate

boat motors are designed so the prop in underwater a certain depth. If you raise the boat (and motor) out of the water, it doesn't work. you need an extended shaft outboard that puts prop deeper in the water. Also water is much more dense than air, so you need a hrdro foil not an airfoil. There were plans and instructions in about a 1960 popular mechanics or science that showed how to build one with a foam slab hull. My dad always wanted to build one.

Nice content mate keep it up

Nice one pal plan bodge should work just fine. Had me laughing

Great project! Armchair quarterbacking: Attaching the foil to the engine does seem like a good idea as it may help act as a cavitation plate of sorts, blocking its tendency to pull air down into the prop flow, allowing the prop to run closer to the surface. Also, attaching the foils laterally outboard may help too as the flow separation due to (inevitable?) stalling may be less likely to cause aerated water to flow to the propeller, also reducing it's tendency to cavitate.

AMAZINGNES!!!

12:00 brilliant!

Linked over from your buddy. Watching ..

Awesome buddy..... I'm just letting you know we need to 3D print a full sized Iron Man working suit, so I can carry the kids to school in it....... might need more than one video. Well done Dave v2...

epic video for a first one! good job

seen a hydrofoil modelboat made a long time ago , the builder made them out of aluminium bar that he shaped intoo a wing contour (though sharp in the front and sharp in the back ) painted the wings after he finished and tested the model and all of a sudden it didnt perform like it was before it was painted after a while he saw flakes of paint comming off the aluminium wings and doing some speed runs passed his boat he found loong bubbles comming off the wings under the water turns out those foils need to be supersmooth or they cavitate on there own and loose efficiency you probably need a longer tail for the outboard to keep the prop in the water when its on the foils to get it a little more stable you probably need to make one set wider then the other , since most of the weight (motor and driver) is on the rear i would make the rearwing a little wider might want to see baout being able to adjust the angles on the first prototypes to get the boat to come out of the water evenly

I liked the porject! It was pretty awesome. I admire your effort to do this. However, I'll be waiting for the next version😎. Welcome to YT btw

great video! bro the quality is great insane for such a samll youtube chanell.

Watch a couple of Johnny Quest cartoons from the '60s . Johnny's dad had some great hydrofoil boats from back then check out the design of these cartoon boats. Great stuff. 👍

GEV ground effect is the fastest safest most efficient way to travel across water. Can be under around 60 hp. Motorcycle or auto or aircraft engine

Thanks for sharing a Poseidon adventure , some Neptuning and you will make Zeus smile , seriously though if the Gods love a trier , your doing something right , and if not I enjoyed watching , informative and well delivered , you really must enjoy / appreciate RAIN MORE ..

Would love to see a follow up video to this. Why not try a dual plane set up? Also, I wonder if greater distance between the two foils would provide for a better balance

Definitely mildly crazy.... This helps a LOT as only mildly crazy attempts such things so CUDOS to you :-) I also have a similar dingy so am inspired towards similar yet different experimentation.... (Yamaha 5hp and a 1960's seagull- lets see what can think of lol).

Nice video mate, subbed to you as well. I'm just curious about what sort of airfoil (eg NACA series) did you use, and whether you did any flow analysis.

Very interested in what kind of glue you used to glue the foil to the boat? This may come in handy for projects I have. Thanks!

I like the pharaseutical ad music in the fiberglassing section lol

Id like to see u put a long shft on i wasnt confident u cld do it but im sure with a longshaft u wil so glad u brought it up

You're like a dizygotic twin of Tom but didn't get the recessive ginger phenotype.

If that dingy was any smaller, it would be an inner tube.😂

Fantastic video. Happy to see Tom cameo. I wonder if 2 smaller foils at the back either side, out the way of the prop, could be a solution. You seem to get plenty of lift from that large wing. I wonder how you would mount it ? Love the project !!

Overall success 🤪 . Well done boys, very entertaining, I thought the 2 hp outboard was always going to be your main obstruction 😉, call me pessimistic.

I used to hydroplane our little dingy, get a slightly bigger motor, we had a 8hp and seat on the front seat

Awesome proof of concept! But I dont understand why you added a second foil, when your first test showed your first foul providing ample lift. If an airplane noses up, you don't add a second wing, you move the wing backwards to put the Center of lift below the Center of mass!!! Your second foil is just adding drag. Seems like you're also setting yourself up for problems by positioning yourself on the gunwale. Good for skippering a floating dinghy, but awkward if you want to balance above a foil. Easy to correct, though! Extend your outboard's throttle handle with a short piece of pvc pipe that fits snugly over it. Now you can helm your dinghy from the Center of the craft -- even from a standing position, if your pvc pipe is Ing enough. Will make it MUCH easier to shift your weight around to balance. Suggestions aside, congrats on the very cool build.

I think you needed less area on the flat section and a shallower V as that's your height control, as you go faster the V Comes out the water so it produces less lift. Go faster, more lift, more of the V Comes out the water until it reaches a equilibrium.

You're foilin' bonkers mate. OK if truth be told I've been playing with the same idea for the past 3 years, albeit I don't intend to make a prat of myself on my own KZfaq channel. I'll just appear on others LOL.

New subscriber sir... Nice content...

Your videos are just way too good, you need to make more videos

I've been wanting to 3d Print a front lip/air dam for my car, but everyone's been saying the structural integrity of ABS won't last! Here's to proving them wrong 😎 thanks for the inspiration since I never considered fiberglass reinforcement

Great IDEA brother LOVED! New subscriber 3D print always a Bad-Short-Cut ...(?)... well old ways are my way .. anyway .. GOD Bless you and yours

I was thinking those foils would come off...just didn't know when. They have lots of leverage on the front edge of each foil so they literally peeled away from the boat. Your foils get you high centered and then the dingy is unstable and wobbly side to side. You need the foils to be wider once you are flying so you maintain stability. Probably move them more to the front and back so you have best possible stability in that direction as well. Your foils don't need to be tall. Just clear the water by 2" and you are set!

Need to do more of this! Your channel is too small for the level of engineering genius you contain! Revisit it!

Interesting idea! However the profile of HF is suboptimal from my perspective. Too thick. That is why it has too much lift and lots of resistance. You can estimate a profile according to a mass and speed in XFLR5 program (free). Also you can just look at wind/wing-foiling or Flying Moth hydrofoils, what profiles do they have. Rear wing (stabilizator) should be smaller and have symmetric section profile, It should be regulated to produce neutral and negative lift for stability. Also you should sit at centerline of the boat. HFs are quite sensitive to roll. Good luck!

Would be cool to see a reattempt in a year, based on new knowledge and ideas

Nice.

you need a hoop shape front one that extends a ways past the gunnels of the dingy and a long shaft outboard of probably at least 15 hp with a large "dolphin fin" on it.

Seeing you use the kitchen as a workshop I was under the impression that you lived alone, not with a girlfriend. I am amazed at her willingness to live with no dining area.

Foils were far to thick and, as you found out, a bit of glue was no where near enough to hold them. Next time use a gauge on the roap from the boat to measure drag.