Introduction: How to "Fly" a Human Powered Hydrofoil - the "Aquaskipper"

About: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of www.zcorp.com, manufacturers of "3D Printer" output devices. His detailed drawings of traditional Pacific I…
The "Aquaskipper" is a human powered hydrofoil made by Inventist.com .
It's similar to the original Swedish Trampofoil, which is no longer available.
There's also one called the "Pumpabike" from South Africa.

They're also called "hull-less watercraft" and "flapping wing propulsion vessels".
You bounce up and down to make the wing fly and propel you.
If you stop you fall into the water and swim back to the dock.
It's completely ridiculous and works really well once you get the hang of it.

It's hard to do at first but that seems to make it even more fun.
Here's what learning looks like:


(After a few days we got a lot better)
Here's Kenny teaching Caglar the starting position.

An ipod formatted copy of the AquaSkipping video can be downloaded here.

Do you like this Instructable? Digg it!

Want to build your own? Here's How!

Step 1: Bounce Down and Up

Find a good place to launch. What you want is a dock a foot or so above the water.
You want water at least 6.5 feet deep according to the manual.
Decide which of your legs is stronger. That's your "pushing foot".
Stand on the side of the dock with the ball of that foot hanging over the edge of the dock.
That's so you'll be able to push off forcefully without your foot slipping.
Rest the rear crossbar of the Aquaskipper on the toes of that foot to keep it from dropping into the water.
Rock forward until the Aquaskipper's front foil is level on the water and step aboard with your other foot.
Lunge yourself and the aquaskipper forward, pushing with your back foot as hard as you possibly can.
Then start bouncing. These two diagrams from the Inventist website show what happens to the gizmo when you bounce. In the "down" part of the stroke the suspension is compressed and the back foil dives. In the 'up" part of the stroke the spring straightens out, the wing swoops up in the water and you glide forward. It's not automatic, you have to learn the skill.
It's hard to describe the motion. It helps to watch the videos many times and have a lot of friends around to make suggestions.

After a week or so of practice you'll be a skillful expert like the folks in the following video.
It shows Aquaskippers, Trampofoils, and other humanpowered hydrofoils at the European Sprint races in 2006:



Step 2: Hydrothopter Evolution, 1953 - the Present

Demographic analysis shows that you're an impoverished 15 year old dreaming of ganging up ten of these with a chinese dragon hiding your friends inside. I know you're itching to go grind foils out of skis with a beltsander right now, but first take a look at what's been done before.

The rest of this instructable covers patents and additional details of human-powered Hydrothopters in order of newest to oldest.

This picture shows Alexander Sahlin riding one of his prototypes in the 90's.

Step 3: Aquaskipper Patent

The pdf icon below will load Shane Chen's 2003 patent for the Aquaskipper.

If you're rushing off to beltsand some wooden foils for a crazy hydrofoil right now, be aware
the foil sections depicted in these diagrams do not resemble the sections of the actual device.

Also bear in mind that Shane's product is well made and it's cheaper to buy one than to spend lots of time building your own.

That said, here are some foil section candidates:
The Eppler E817 and "Ogive" sections are popular with Hydrofoil Society Members.
NACA 63412 and H105 are used by the Moth hydrofoil dinghy and others made by the same folks.

Step 4: Pumpabike Patent

The pdf icon at bottom will load Michael Puzey's patent for the "Pumpabike".
His website has a lot of good info, including owner's manual.

Step 5: Trampofoil Patent

Alexander Sahlin, inventor of the Trampofoil obtained Swedish design patent number 98-0088. Swedish Patent and Registreringsverket.

I haven't been able to find a copy, but if any of you do, please send it to me.

Alexander has gotten into some interesting new projects and no longer sells Trampofoils. The old Trampofoil website has gone offline, but you can still find it using the "Wayback Machine". That's where I got the following pictures of the Trampofoil.

His old website has the story of how he developed it with pix of the prototypes.

Step 6: Flying Fish 1983

The original pedal powered hull-less hydrofoil, the "Flying Fish":



The flying fish video is from Mark Drela's Decavitator website, now only available via the WaybackMachine:
http://web.archive.org/web/20051218183752/lancet.mit.edu/decavitator/VideoClips.ff.html

http://members.aol.com/jfreeent/hf.htm says:
"The first hydrofoil to fly was probably the "Flying Fish"; It was essentially a bicycle with foils instead of wheels. It had no floats at first, and was launched off a pier on rails. Their flight was
first published in 1984. If your PC can run video, the "Flying Fish"link below will show the essential components of all hydrofoil research. . .GETTING DUMPED !! That's Allan Abbott on the hydrofoil, and probably Alec Brooks doing the "rip cord". "

The photos are from http://www.ihpva.org/HParchive/ Human Power, the Journal of the IHPVA Vol 3 no.2 winter 1984 in the lead article "The Flying Fish" written by Alec Brooks. The captions read: "Allan Abbott flies by at about 12mph" and "The Flying Fish, weight: 39lb, max speed: 14+ mph. Note surface follower on front strut."

Step 7: Wasserlaufer 1953

This was the first human powered hydrofoil. The name means "water strider", the waterbug that scampers on the surface of the water:



From http://www.human-powered-hydrofoils.com/history.html
:" This is the first human powered hydrofoil ever. It was invented and designed by the bavarian engineer Julius Schuck. In 1953 it was presented the first time in the german Tagesschau (News) and the inventor himself rode his hydrofoil on the river Isar in Munich. In the 1978 movie Gizmo by Howard Stern the Wasserlaufer has a small part. This movie was reporting about crazy inventions of past days.
The Wasserlaufer used Flapping Wing Propulsion far before anybody else even thought about this way of propulsion. Below is the link to the News Video of the Wasserlaufer. C© Bilder, Videos Dr.-Ing. Wolf-Dieter Schuck"

Step 8: Pogofoil 1989

Parker McCready, the designer, has a page describing this craft which has a main wing "of a carbon/epoxy composite, is about 2 m in span, uses a NACA 4415 airfoil section".

Here's Mike Lampi's video of the Pogofoil in action: