Boots to walk on water

[Max_Connor]

Hey!
Not sure where to post this, so I'll do it here.
I wanted to ask if anyone knows anything about real boots that would allow you to walk on water - maybe someone has created anything similar.
I'm talking about hollow boots that resemble boats and keep your body on the surface of water by displacing water. It shouldn't be inflatable ones like those you can see on YouTube - those are merely toys from aliexpress that are poorly designed. The boots shouldn't have any engines or machinery parts.

I came up with a small picture that explains the general idea, see it below. A couple things I would add: the polymeric fabrics should be wrapped around some metallic framework, which should be sturdy enough to withstand human weight when walking and running and be lightweight at the same time. The volume and dimensions of the boots can be slightly adjusted.

The questions are:
- Has anyone created such things? Is there anything similar to than on the internet (except those inflated boots from ali)?
- Is this a good idea in general and would water walking with such boots be comfortable after some training?

I would be thankful for any advice and thoughts.

 

[rb1957]

this has been done, not very successfully. the problem is the adverse metacentric height ... the CG of the person is higher than the CG of the buoyancy, not to mention the drag of moving these things in water. The 3rd point (particularly "running" in these things) is IMHO pretty laughable.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[Max_Connor]

Thanks, rb1957

Yes, the metacentric height and buoyancy are the main problem. I've done some rough calculations, and think it is partly solvable, if you mess with dimensions and technique of using these.

If you take average CG of human body, it will be about 1/2 of average height - that is about 85cm (34in) from the ground. Let's say we make the boots a bit heavy - 5 kg (10 lbs) each, together 10 kg (20 lbs). This will keep the height of CG about the same. Let's say you slightly bend your legs and crouch a bit to lower your CG while using boots - that will drop it to about 60-70 cm (about 2 ft) from ground.
Then you make the 'boots' wide enough so the distance between buoyancy center and CG is comparable to half the width of shoes (not more than 1.5 times longer). If the center of buoyancy is in the middle of the shoes (about 15 cm from the 'keel'), then this distance is roughly 50 cm (20in).

50 over 1.5 is about 30-35cm (12-14in), which should be half the width of the shoes. But considering you have 2 of such boots, you can roughly cut it in half (only half of your weight for each one), and get that 12-14 in should be the full width of each 'boot'. That is acceptable.

You can also experiment with the height of the shoes, optimize the dimensions...

The drag can be partly solved by the streamlined shape and trained legs.

I figured that running could be easier because you don't stay in place for long enough to flip over. You rather quickly hit the water, upon fast impact it acts more 'solidly', and with enough area of contact, you can run on surface like some lizards do?

 

[rb1957]

I wish you well with your endeavours.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[zeusfaber]

I imagine that the lack of ability to react static horizontal forces means the user is going to have to learn some new standing and walking techniques.

Standing still will require positive effort to stop your feet drifting apart and this will become a bigger problem when you lift one foot to take a step forward. You may want to tie the boots together loosely.

What's the walking technique? Is the plan to put aft-facing scoops onto the underside of the boots to act as paddles, then just shuffle along with both feet in the water (this has certainly been done before) or were you hoping for a more natural gait that involves lifting each foot clear of the water in turn to swing it forward? If you want the natural gait, then you will need to find some way for the immersed boot to provide enough righting moment to allow you to lift the other foot - otherwise you're straight back to shuffling along.

Where it's been done before (see

https://www.youtube.com/watch?v=vfeTHX-qYac

for instance), they seem to have stuck with a shuffling gait.

 

[Compositepro]

First calculate the volume and dimensions required to displace enough water to float. Each foot-float has to support the full weight of the person plus the other float in order to be able to take a step.

There is also a suction created when trying to lift a float from the water, which takes a significant time to break. Much like walking through mud.

When walking on land your feet are placed close to under your center of gravity with each step. Try walking on land with floats on your feet. Floats prevent you from putting your feet close together. You have to walk like you have saddle sores, like a cowboy after a long horse ride. So you cannot get your center of gravity under your center of buoyancy when you switch from one foot to the other. So you have to shuffle on two feet rather than walk.

Walking on water is like walking on ice. There is no static friction, although there is a viscous friction. Viscous friction is actually very small. When you slip on ice it is actually a microscopic layer of water that you slip on. Most resistance to moving in water is due to the mass (inertia) of water that must be displaced.

So there are fundamental reasons why you cannot walk on water.

 

[rb1957]

'cept you can walk on ice. Dry ice (no, not frozen CO2) is pretty easy; wet ice is hard (without special boots or changing your gait to more of a slide ... when you have low friction, use it to your advantage).

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[LittleInch]

Never going to happen.

Try looking at water bikes like this

https://hydrobikes.com/

If you want to just convert that into a sloped treadmill which turns a propeller?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[waross]

Rather than build, go to the building supply store and buy some rigid foam insulation.
Then just cut to size.
By the way, try tying a 20 pound weight to each ankle and see how much fun walking is.
Then put on a pair of snowshoes to keep your feet apart and try again.
Call it "Proof of Concept."

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Max_Connor]

Thank you all for your replies!

The video with the military boots that zeusfaber sent is actually really close to what I was imagining. Shuffling is the only convenient way to maneuver with those.

Now I see that hydrobikes or simple small inflated boats are better in all ways, so yes, the idea was bad.

 

[3DDave]

There are few truly bad ideas. Even those that don't work while not resulting in lasting physical harm, are ones that are useful to serve as a caution to others

If you search for videos with "shoes walk on water" you will find many solutions to the problem, some very clever, some vastly imperfect.

The more interesting task is to do a detailed analysis of why making footwear to enable walking on water is such a difficult task. While it may not lead to a great solution, it may produce insights into other problems that seem unrelated at this point.

For example, to step forward one has to lean forward. To continue to lean forward and provide forward momentum there has to be force, and therefore a reaction force. On land this is by friction with the other foot. Water provides little static friction, as mentioned above.

It also gives experience in research. Among the 7 Billion people now alive and the Billions who died before, even a tiny percent looking to solve a problem will likely turn up attempts. The first thing the Wright brothers did in their path to a powered airplane was to write to the Smithsonian Institute for any information available on the design of airplanes. In testing one of the more reliable sources about wing design, they found that source to be wrong. Understanding that failure was helpful to later understanding how to design a propeller.

 

[SWComposites]

The answer is: stand up paddle boards. Go down to your local water sports center an buy one.

 

[3DDave]

Not a great answer for a student.

Now, getting some bamboo and a life-vest, that't the ticket.

https://www.youtube.com/watch?v=FdVrQIR9Nzs

Here's some college credit fun

https://www.youtube.com/watch?v=jmyUnE-jT20

 

[rb1957]

I agree with 3DD, and maybe this is the point of the student exercise ... figure out which ideas to embrace and which to run away from.

How about a "backpack" (possibly a small, large?, truck) that could freeze just enough water for just long enough to walk over ... 10' diameter, 6" deep ... 150 ft3 of water to ice. ok, 1/2 this starting from the shore, then advance 2ft so increments of 10ft3 ??

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[LittleInch]

I've been thinking about this and maybe there is option to look at this more like a cross country skiing set up?

So fit a void approx 0.1m wide, 1.4m long x 0.5m deep or maybe a bit less. That would take care of longitudinal stability, but would need the two skis tied together to avoid doing the splits. Maybe add some out riggers?

Add in some floats on your poles with some plates or ribs to give you some purchase on the water.

Then do what they do on the normal skis and fit one way chevron type devices so as you glide one ski forwards they fold up and allow it to move then dig into the water on the reverse cycle. Those skis have hinged attachments on the skis to allow the normal foot walking motion.

Maybe add some longitudinal fins to give some lateral stability and you might have invented a new summer sport for cross country skiers!

Actually already been done!

https://newatlas.com/abh20-cross-country-water-skis/29946/

Maybe you can improve on it?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Struct123ure]

Hire a lawyer.
I imagine the first thing that would happen when someone new steps into water is they fall over and (these being strapped to your feet I assume)would float up to the surface while the head sinks to the bottom.
And then they drown, that's where the lawyer comes in.

 

[driftLimiter]

And then they drown

lol this is the first thing I thought about when I saw zeus' video.

 

[zeusfaber]

The closest I've ever come to drowning was thanks to buoyancy in the wrong place - helicopter underwater escape drills with a single-seat liferaft strapped to my bum and then the lifejacket didn't inflate (for reasons that were largely my own fault).

 

[LittleInch]

Not that much different to a kayak really.

First thing you learn is how to get out upside down.

A quick release system needed for sure.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[3DDave]

Perhaps a cross between walking on water and the concrete canoe competition?

Did I just hear a university legal team gasp?