[HN Gopher] 'Underwater bicycle' propels swimmers forward at sup...
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'Underwater bicycle' propels swimmers forward at superhuman speed
Author : peutetre
Score : 372 points
Date : 2024-05-08 13:13 UTC (9 hours ago)
(HTM) web link (newatlas.com)
(TXT) w3m dump (newatlas.com)
| tamis022 wrote:
| Motorized propellers have existed for 20+ years and are routinely
| used in spearfishing. What the heck is the news!?
| https://www.amazon.com/Nautica-Skipper-Seascooter/dp/B0BLP9Z...
| Mordisquitos wrote:
| What about non-motorised propellers?
| bilsbie wrote:
| I've always wished those were slightly cheaper and slightly
| faster.
|
| 4mph and under $250 and I'm sold!
| Pxtl wrote:
| I assume that now that we're in the world of hyper-cheap
| batteries I'm sure we'll see somebody do that soon enough.
| cimm wrote:
| How should one take a turn in a swimming pool with this?
| giardini wrote:
| Avec difficulte'!
|
| Design engineer: "Turns? Turns?!"
| Vox_Leone wrote:
| Cool. More like an underwater 'monocycle', though. Make it into a
| full body struct in Y shape acting as kind of both 'guidon' and
| secondary propulsion axis -- more blades, an underwater tricycle.
| :)
| Milner08 wrote:
| Is a Monocycle something different to a Unicycle?
| szszrk wrote:
| Apparently! I did not expect such a nice find after asking
| search engine this:
|
| https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1700041
|
| > There are two main types of single-wheeled vehicles. In a
| unicycle, the rider sits above the wheel. These vehicles are
| recognizable by most people. Less well known is the
| monocycle, where the rider sits inside the wheel.
| jamiek88 wrote:
| The famous South Park episode was a monocycle!
|
| https://en.wikipedia.org/wiki/The_Entity_%28South_Park%29
| porphyra wrote:
| yeah likewise the dicycle has two big wheels side by side
| haha
| aidenn0 wrote:
| You must have missed this:
| https://news.ycombinator.com/item?id=40080406
| tokai wrote:
| "Seabike says the prop turns slowly enough that you can safely
| use it at the local pool"
|
| Felt a bit iffy about this claim. But looking at the research it
| seems cadence lowers normally when cycling under water.[0] Fun
| device. I wonder which pedals would be best for barefoot
| riding(?). Maybe those strapped ones fix riders like to use.
|
| [0] https://ieeexplore.ieee.org/abstract/document/23706
| Rinzler89 wrote:
| Yeah I wouldn't want to get hit in the face by those props at
| the pool. Accidents can always happen.
| giardini wrote:
| Flip turns would be clumsy at best.
| psadri wrote:
| Reverse all thrusters!
| bilsbie wrote:
| I wish we could find a good way to bike over the surface of the
| water. I haven't seen anything that's not slow and cumbersome.
| debacle wrote:
| Anything you choose will be cumbersome because you can't create
| friction on the water (well...), your ability to move is based
| on your ability to move water around you.
|
| There are solutions that leverage a pair of catamarans and a
| track system, or a prop. These tend to move very slowly, much
| slower than a canoe or kayak. The water wheel style systems
| seem to move faster, but you can just get a pedal kayak and
| will be the fastest human powered craft on the water.
| etrautmann wrote:
| I've always wondered why nobody has created something that
| looks like a catamaran with two rowing shells and a road bike
| on top directly connected to a prop. That would have minimal
| drag, an optimal body positioning for using leg muscle
| strength, and would be fun and intuitive to pilot (facing
| forwards, feels like biking, etc). The obvious downside is
| that height above water may be an issue so the catamaran
| would have to be wide, but it seems solvable.
| debacle wrote:
| They have, they're still quite slow.
| hetspookjee wrote:
| I believe an ocean crossing was even done with this kind of
| vehicle.
| mhb wrote:
| http://www.castlecraft.com/seacycle.htm
| alanbernstein wrote:
| https://www.shuttlebike.com/en/
| peutetre wrote:
| Hydrofoil bike:
|
| https://manta5.com/
|
| https://www.youtube.com/watch?v=heSPbLHftKw
| itishappy wrote:
| Foil boards are getting semi-popular for kiteboarding. They
| can be self-powered as well using a jumping motion. They also
| make e-foils with small electric props.
|
| https://www.google.com/search?q=foil+board
| causal wrote:
| That's battery powered though, and looks pretty heavy. I
| think I'd sooner go for one of these https://liftfoils.com/
| alanbernstein wrote:
| I can only imagine this is slow and cumbersome, but I love the
| idea of it working with your existing bike:
| https://www.shuttlebike.com/en/
| Apes wrote:
| I'm curious how this compares to using fins. Just at a glance, I
| suspect it causes more drag and is more cumbersome to swim with.
| But the big thing is if it's more efficient overall than fins.
| onemoresoop wrote:
| Looks a more uncomfortable than the fins (especially the lumbar
| lordosis part) but I imagine this should be way faster than
| fins.
| Sprint9935 wrote:
| Id imagine this uses stronger muscle groups. Think about how
| much force you can make pushing down with your leg, compared to
| moving it forward or backwards when you are upright.
| karaterobot wrote:
| > This jigger, according to the manufacturers, makes you
| handily quicker than an equivalent swimmer with fins on.
| rhaps0dy wrote:
| What's the advantage of this over foot fins?
| BurningFrog wrote:
| I think it uses much stronger muscle groups.
| carlosjobim wrote:
| Maybe the muscle movements are more natural and comfortable.
| Swimming with high power foot fins is probably as fast as
| this, but it gets very tiring real fast.
| karaterobot wrote:
| > This jigger, according to the manufacturers, makes you
| handily quicker than an equivalent swimmer with fins on.
| julianeon wrote:
| I can think of a huge one.
|
| I live near a fairly dangerous ocean in SF where I've gone
| bodyboarding with a wetsuit and fins. I'm concerned that, if
| caught in a current, fins are not enough to propel me out of
| it.
|
| This would. The extra power and ease of propulsion could make
| all the difference.
| SOLAR_FIELDS wrote:
| I guess the logistics of the thing make all the difference
| here. Is this something you can detach from a surfboard and
| equip while being carried out in choppy waters? Could be
| either really useful or useless depending on that answer
| ben7799 wrote:
| You just need to get familiar with the correct way to handle
| a current like that. It's not to fight it.
|
| Especially with a bodyboard and fins doing the right thing
| does not require a ton of strength and shouldn't be
| stressful.
| matsemann wrote:
| Didn't look to go much faster in the video than what I can do
| with my freediving fins.
| deltarholamda wrote:
| From the videos, not much IMO. Presumably the guys doing it in
| the videos have a fair amount of experience with it, and it
| looks... awkward.
|
| Flippers have a great deal of fine control in all axis, and
| this doesn't look like it does. I'm a pretty fair diver, but
| when you see guys who dive all the time, they look like they
| were born with those flippers.
|
| And free divers? I can't imagine them giving up their fins.
| They take advantage of the really long and strong muscles in
| the legs.
| bilsbie wrote:
| There are a bunch of small watercraft I really want to try. It's
| hard to justify the expensive.
|
| The hydrofoil board with a prop and motor looks really cool.
|
| Just not sure what the learning curve is like and kind of worried
| about hitting something and flying off.
| SkyPuncher wrote:
| Those e-foil look amazing, but the prices on them are insane.
| Like multiple times the price of an e-bike.
|
| I, frankly, don't understand it. They aren't particularly
| advanced devices.
| ljf wrote:
| I spent a bit of time looking into building your own - from a
| parts point of view (buying new) you are still looking at
| PS1000 to more like PS2500 worth of batteries, controllers,
| motor and prop, plus the foil and the board you attach it all
| to. Then you need to make, seal it and make it 'sea worthy' -
| would be hundreds of hours of work for me.
|
| I'd happily buy a well made new one for PS3000 if that was
| what they cost, but half that price is a new good solid
| paddle board - so I can see why you can't get the same plus
| all the electronics you need for PS3k.
|
| We can hope in time the costs come down, but as a niche
| sport, it will be some time, if ever. Have you seen the cost
| (and service intervals!) of a new jet ski? All simple tech,
| but they don't come cheap and need a lot of looking after.
|
| I can still dream though.
| amenhotep wrote:
| They're a toy being sold in small numbers to people who live
| near lakes or can fit driving to the lake with it into their
| life easily enough to want to buy it - good proxy for having
| a bit of disposable income to throw around. Market can bear a
| high price, not enough volume to make competition appealing
| => PSPSPSPS
| grayrest wrote:
| There's a DIY forum for building those[1] but I think tow
| boogies[2] are more practical as a project. The idea is a
| battery box, controller, and motor on a boogie board and
| shifting the weight of the person being towed allows for
| steering.
|
| [1] https://foil.zone/ [2]
| https://www.youtube.com/watch?v=S9z6BP8Y42U
|
| Since the original article is about human power, I'll also link
| to this foil[3] which is for pump foiling long distance. I had
| run across the channel well before that and thought his goal
| for a half hour was goofy when people were getting 90s or 2
| minutes so I was quite shocked when it actually got built.
|
| [3] https://www.youtube.com/watch?v=WfJbF0xkUOY
| danielvaughn wrote:
| At first glance, the idea of clip-ons in the water seems quite
| dangerous.
| davidw wrote:
| I noticed that too. Clipless pedals seem like they could be
| kind of stressful for someone not used to them. Or even someone
| who is, but is using them in a very unfamiliar situation.
| vitiral wrote:
| Really, why? Because you might drown?
|
| Try holding your breath and just floating, arms at your side
| and legs not moving. You will bob to the surface. Then quickly
| release your breath and snap your neck back to take a new one.
| Repeat. That's all it takes to not drown. You could almost do
| it as a quadriplegic (though I'm not 100% on "water balance" in
| that case).
| bluefirebrand wrote:
| This is not true if your feet are clipped to an object heavy
| enough to keep you under the water though
| xmonkee wrote:
| This device is buoyant, according to the article
| cassianoleal wrote:
| Which will make your feet float, driving your head
| underwater.
| 4ad wrote:
| No, not all people are buoyant. Some people sink. I used to
| be able to float even with my lungs empty, but after losing
| 30kg I can now _walk_ on the bottom of the pool will my lungs
| full of air.
|
| Also, even if you are buoyant, it does not follow that being
| strapped to some device means you can't drown.
| simonbarker87 wrote:
| Some people (myself included) don't float like this. I try
| basically every time I get in the water and my legs drift
| down to just after 45 degrees and then I slip under
| completely and don't resurface until I give in and swim back
| up.
|
| People who can float never believe me, but enough have now
| seen me in the water that I know I'm not "doing it wrong" I
| just don't float.
|
| The people who've seen me try it in water always say
| something along the lines of "huh, I thought everyone could
| float" we've done a few goes.
|
| Most people float, I'm just not one of them.
| dh2022 wrote:
| Have you tried filling your lungs with as much air as
| possible?
| ben7799 wrote:
| This is the answer. You're supposed to learn this if you
| take quality swim lessons.
|
| I was a Red Cross Water Safety Instructor and lifeguard.
| I taught plenty of lessons to sub-10% body fat adults who
| had this problem. I generally have this problem too.
|
| I can still float all day effortlessly.
|
| I would totally try this toy out if it was at a resort
| and I could try it free or for a small charge. I think I
| wouldn't likely buy one but I would definitely enjoy
| trying it.
|
| It is extremely clear to me this is a toy for expert
| swimmers. Anyone who has any fear at all of it should not
| try it. A lot of the comments read to me as people who
| are not good swimmers and aren't being straightforward
| about it and are projecting things onto the device.
|
| But I also see no reason why you can't use this thing
| with a PFD. For something like a snorkeling program you
| could let people use it with a PFD.
|
| A lot of people who can't swim freak out and have poor
| control of their breath. That's why this is a sticking
| point in lessons sometimes. You can tell someone to slow
| their breathing and hold more air in their lungs, but
| they are basically freaking out breathing fast and they
| have no control.
| s1artibartfast wrote:
| Does no part of your body stay on the surface?
|
| On average, people stop floating around 10-15% body fat,
| but this varies based on lung capacity and bone size.
|
| Lung capacity is often an under appreciated factor
|
| Inflated Lung density is about 25% relative to water, fat
| is 95%, organs are around 105%, and bones are about 185%
| epiccoleman wrote:
| You are not alone!
|
| I was in swim lessons since I was like 3, on swim teams
| from age 8 to 18, I love the water. But I never cracked the
| code of floating.
|
| I can _sort of_ float on my stomach, but this is not
| especially useful. And I definitely have some degree of
| buoyancy, I have to let out air if I want to sink to the
| bottom. But my default state in the water is to bob
| uselessly near the surface. Even with a big breath, even if
| I try to hold them up, my legs drag me down.
| itishappy wrote:
| Same here. I can almost float when equipped with a 3mm
| closed-cell shorty wetsuit (very buoyant), but my legs
| still pull me vertical...
| ninininino wrote:
| It's just math. If you are too lean and muscular, your
| density is much higher than if you have a higher body fat
| composition, but there's also an element for non-fat people
| and adults that they need to 1) hold their lungs more full
| than normal with diaphragmatic breathing, holding the
| breath in for longer, and exhaling more shallowly than a
| full exhale that they can apply, as well as 2) leaning back
| much farther and tilting your head back much more than
| you'd expect to have to. Legs sinking is a classic problem
| for swimmers that occurs due to body alignment issues and
| especially not leaning your head and neck far enough back.
|
| You need to be an outlier to not be able to overcome a body
| composition / density problem with techniques #1 and #2
| above though, without observing you no one can really say
| if you're applying those techniques properly.
| loeg wrote:
| Can you elaborate on that?
| danielvaughn wrote:
| clip-ons lock your feet to the device. If you find yourself
| needing to suddenly swim away from the device for any reason,
| you better hope that you can easily clip out. On a bicycle,
| you can do this fairly easily because you're on ground with
| gravity. In water, it could be much more challenging to clip
| out.
| loeg wrote:
| > If you find yourself needing to suddenly swim away from
| the device for any reason
|
| Can you elaborate on that part?
|
| You would set the cleat retention tension lower than for a
| bicycle. (But also this product is ridiculous, no one is
| actually using it.)
| cassianoleal wrote:
| Especially clipping your feet to a bouyant device!
| xhkkffbf wrote:
| Better than clipping them to a non-buoyant device. Or worse,
| the classic cement overshoes.
| cassianoleal wrote:
| If it's non-buoyant and not very heavy, it's easier to
| control and stay afloat than if it pushes your feet upwards
| to the surface.
| neerajk wrote:
| > The nominal mode enables motion through the water at 3.6 km/h,
| and for speed-seekers, the SEABIKE can reach a maximum of 7.9
| km/h - much faster than normal swimming speeds or even flipper-
| assisted swimming.
|
| https://www.nauticexpo.com/prod/seabike/product-68606-564117...
|
| Pretty fast, but "superhuman"? For short distances Michael Phelps
| can swim faster :)
| mrfox321 wrote:
| Michael Phelps is an alien..
| deltarholamda wrote:
| Incorrect, he is an evolved dolphin.
| badcppdev wrote:
| So dolphins are aliens??
| el_duderino_ wrote:
| Thanks for all the fish!
| willcipriano wrote:
| Traveling at that speed for a long distance would be beyond
| human capabilities, wouldn't it?
|
| Super just means beyond, not way beyond. I blame Superman for
| this notion.
| sandworm101 wrote:
| Not really. Most serious lap swimmers can do a kilometer
| every 20 minutes sustainably, akin to a marathon runner's
| pace (Sprint pace would be 100m/minute, with 50m/minute being
| what you would see in the fast lane of most recreational
| pools). So 3.6 kph isn't all that different, maybe a little
| faster than average but I assume they were also using a
| better-than-average bicycle person when doing the test.
|
| There real advantage here is that you can use leg muscle.
| Distance swimming is all about upper body muscles, with legs
| being the afterburners only really used for sprinting. This
| machine would invert that arrangement.
| willcipriano wrote:
| Perhaps the question must be then is Michael Phelps (or
| whoever) faster on it?
|
| If he or someone else breaks the record with it, he's going
| beyond human level speed. Until then this may only have the
| potential to do so.
|
| I imagine the first bikes were slower than the top runners
| of the time? I see potential for the idea.
| sandworm101 wrote:
| >> is Michael Phelps (or whoever) faster on it?
|
| Nope. He would be horrible with this device. That would
| be like asking a champion sprinter to compete in a
| wheelchair race. He would be using totally different
| muscles, legs rather than arms, and get schooled by most
| everyone with a longer history. A champion bicycle rider
| would do better on this contraption than any champion
| swimmer.
|
| (Due to water's density, champion speed swimming is also
| 80% technique and body shape rather than muscle/cardio.
| So until the technique is developed, nobody would be
| "good" with this thing.)
| iambateman wrote:
| TBH I think Michael Phelps would do just fine with this.
| :D
| lupusreal wrote:
| Not sure why you're downvoted. Five minutes for a 500 Free
| is a pretty typical time for boys on highschool swim teams.
| sandworm101 wrote:
| It has been a while since I was a competitive swimmer
| (AAA+) but imho five minutes is a very good time for
| 500m. That would be faster than 95% of master swimmers at
| such distances, and well into the 0.01% of humans
| overall.
| lupusreal wrote:
| Ah shit your right, I had in mind 500 (yard) Free. 500
| meters in under five is very good, but still attainable
| by the upper tier of highschool swimmers I think. I could
| reliably do 500 yards in under five and was a "B relay"
| tier on my team.
| keybored wrote:
| The almost-meter Yard has got to pack its bags and go
| home soon. What is it even doing at this point other than
| causing naked numeral confusion.
| lupusreal wrote:
| A lot (most?) of American school pools are built to the
| yard, so it's going to stick around for a long time I'm
| afraid.
| sandworm101 wrote:
| A couple things. 500m is not actually an event. The event
| is 400 meters, which is roughly 500 yards. And a yard
| pool will only be 25 yards, not 50. So yard times are
| "short course" and not really valid for serious
| competition. A 25-meter/yard pool has fewer turns making
| them faster, much faster in breaststroke. And a 500-yard
| in a 250meter pool will include one extra lap, one extra
| turn, than a 400m in a 25-meter pool. Short-course/yard
| times all seem faster than they really should be,
| regardless of distance conversions.
| dyauspitr wrote:
| A mid tier marathon runner can do a _mile_ every 20 mins,
| not a kilometer. It's a significant difference.
| sandworm101 wrote:
| I meant the effort required for the pace, not the literal
| speed. For a skilled swimmer, 20min per km can be
| maintained for a few hours, like a runner maintains
| marathon pace for a few hours.
| rrobukef wrote:
| Imagine how fast Phelps could swim with this!
| matt_heimer wrote:
| Given that he optimized his training for swimming and not
| cycling I think he might do better with fins. His top speed
| of 7.2 - 9.6 km/h is freestyling without fins. He reached
| somewhere around 13 km/h using a Lunocet monofin.
| globular-toast wrote:
| For short distances Usain Bolt can run faster than most people
| can cycle.
| dyauspitr wrote:
| For very, very short distances I can run faster than most
| people can cycle.
| tetris11 wrote:
| For mere fractions of a second, I can outwalk a jet.
| IncreasePosts wrote:
| Well that's easy, jets can't walk.
| richardw wrote:
| Main difference is recruiting much larger muscles, so at some
| point most humans will be faster over a longer period with the
| widget. Let Phelps train with this for a couple months and he'd
| be faster. Although probably sad, because he likes swimming.
| Pxtl wrote:
| I mean swim fins also propel swimmers at superhuman speeds
| (aside, it would be really cool if there was a proper competitive
| community for stuff like that, like how on land we have races for
| runners and races for cyclists; edit: Google informs me the
| competitive sport has world championships and is called
| "finswimming"). Is there any quantitative comparison between this
| doodad and fins?
|
| It doesn't even have convenience going for it since you have to
| strap into it, so it's probably almost as much of a ball-ache to
| put on as fins, plus the awkward problem that it's hard to stand
| up.
|
| If they can make it work without the waist strap (or have super-
| quick disconnect for that strap) I could see that convenience
| being nice, but still, I'd like proper comparison with fins.
| thelastgallon wrote:
| This can be another transportation option, like walking and
| biking infrastructure. Cities like Venice can offer this today.
| Other cities which will be underwater eventually will get this
| water infrastructure built for free.
| uncertainrhymes wrote:
| I swim because I enjoy it, not because I'm trying to get
| somewhere fast.
|
| This seems awkward and I bet you have to use your arms just to
| counterbalance the twist you'd get on each 'stroke' of the leg.
|
| So even though I think it's goofy, I bet I'd like whoever came up
| with this. Someone who put a ton of effort into building
| something they thought would be interesting despite a thousand
| people telling them it's goofy.
|
| Good on them.
| 404mm wrote:
| Balancing this device must have been a good problem to solve!
| All I can think of is "where does the other end that stick go?"
| whamlastxmas wrote:
| Your blow hole, clearly
| a_c wrote:
| Two propellers spin in different directions might solve it I
| guess
| 4gotunameagain wrote:
| That will counter the rotational force, but not the
| transversal up your butt.
| abecedarius wrote:
| Maybe design a pogo-stick-like action, pushing with both
| legs together?
| gklitz wrote:
| > I swim because I enjoy it, not because I'm trying to get
| somewhere fast.
|
| I run because I enjoy it, not because I'm trying to get
| somewhere fast. But I also bike because I enjoy it, not because
| I'm trying to get somewhere fast.
|
| You seem to assume that because this thing is faster, it must
| automatically be less enjoyable. That's not the case for bikes,
| why should it be the case here? In my opinion it sounds fun,
| and would probably be enjoyable.
| uncertainrhymes wrote:
| That's a fair point. My (untested) assumption would be that
| it would be cumbersome and weird, and I wouldn't be
| 'swimming'.
|
| If I were to guess at their motivations, it might be 'what
| could make me go faster in the water and also be enjoyable'?
| I'd try it out of curiosity, sure, but I'm pretty sure it
| wouldn't last beyond the novelty for me.
| DrammBA wrote:
| Biking is definitely cumbersome and weird at the beginning,
| and it wouldn't be considered "running" by any stretch of
| the imagination.
| matt-attack wrote:
| A bike is just a way for runners to cheat.
| giraffe_lady wrote:
| Fixed gear bikes are the most fun so it kinda is true of
| bikes.
| kiba wrote:
| Running does make pedestrian locomotion more tolerable. Save
| me some money versus using electric scooters though I think
| electric scooters are still faster.
| jerlam wrote:
| Maybe not necessarily "faster" but there is an idea that
| adding any kind of technology should be avoided for
| recreational activities. For example, you can mountain bike
| with a fully-suspended e-bike, or you can struggle with a
| hardtail or even a road bike. Different kinds of fun, but in
| the former you'll wonder if it's the technology doing all the
| work.
| mhink wrote:
| I don't think this argument holds water (pun intended),
| though, since this device is completely human-powered.
| Johnny555 wrote:
| _there is an idea that adding any kind of technology should
| be avoided for recreational activities_
|
| How do you draw the line at "any kind of technology"? Isn't
| the bike itself "technology"? How about pneumatic tires? Or
| computer designed tread for optimal traction? Is a bike
| suspension too much technology? How about electric assist
| that can help you up a hill but won't propel the bike
| without you pedaling along with it?
| nordsieck wrote:
| > there is an idea that adding any kind of technology
| should be avoided for recreational activities.
|
| That's a pretty weird idea.
|
| Skis, snowboards, or snowshoes make traveling on snow,
| especially downhill, much more fun.
|
| Bicycling, rollerblading, skateboarding (basically using
| anything with wheels) is very commonly considered more fun
| than running.
|
| Most people who swim in cold water prefer using a wet suit
| rather than toughing it out.
|
| And it's pretty fun to use a boat, surfboard, or scuba gear
| rather than be stuck swimming without any aids.
| shkkmo wrote:
| > Different kinds of fun, but in the former you'll wonder
| if it's the technology doing all the work.
|
| "All the work" is useless hyperbol. There are things that
| simply can't be done on a road bike. There are things that
| can be done on a road bike without a significant loss of
| safety.
|
| Sport technology can reduce the skill required for certain
| things, but it also tends to extend the envelope of what is
| possible. It is almost never correct to think of technology
| doing all the work but rather to think of it as an ability
| multiplier.
|
| There are of course, times when it is beneficial to
| practice without a specific piece of equipment. Either for
| a challenge or/and to hone a specific sub skill.
| password54321 wrote:
| >You seem to assume that because this thing is faster, it
| must automatically be less enjoyable.
|
| The problem in this case is that the device is doing part of
| the swimming for you.
| zardo wrote:
| I don't understand how this is different than the running-
| bicycling example. How does this swim for you but a bicycle
| doesn't run for you?
| matsemann wrote:
| But if you wanted to swim fast you could just use flippers,
| and be much more agile.
| Broken_Hippo wrote:
| My favorite way to swim is with those flippers - because I go
| fast.
|
| Going fast doesnt mean not enjoying it.
| lupusreal wrote:
| Yep, going fast with flippers feels great.
| LtWorf wrote:
| Feels less great for all the people in the pool that you
| kick.
| Broken_Hippo wrote:
| You don't _have_ to do it in a crowded pool.
| hnthrow289570 wrote:
| It's pretty neat. I'd want to try a version with a linear
| motion that drives the propeller for the counterbalance
| reasons.
|
| I could see this as an alternative to fins offered at
| snorkeling places. That would make a great test environment
| too.
| LtWorf wrote:
| If you live somewhere with currents, it could be good to be
| able to swim at all.
| arturkesik wrote:
| I come from family of scuba divers, and the scuba divers are a
| perfect market for this I think - pretty rich, pretty lazy and
| have to cover a lot of distance underwater
| bbarn wrote:
| My wife and I rented the double subnado things last time we
| were out of town diving. Seems that fits the pretty rich and
| lazy market much better.
| jpm_sd wrote:
| I'd give it a try, but the "crotch rod" mounting strategy looks
| awfully uncomfortable.
|
| Engineering students have been building "underwater bicycles" for
| human-powered submarine competitions for decades!
|
| https://internationalsubmarineraces.org/
| yawpitch wrote:
| If it's powered exclusively by a human then _whatever_ the
| results, they're not "superhuman".
| cassianoleal wrote:
| Super == above, over, beyond.
|
| If it augments the human's capabilities, it's definitely super!
| yawpitch wrote:
| Super, sure, superhuman, no... someone running in shoes isn't
| superhuman compared to someone in bare feet, anymore than
| someone using a block and tackle to lift or a wheelbarrow to
| transport is engaging in superhuman acts just because they've
| used their very human brain to leverage a simple machine.
|
| Something like this expands the envelope of what is,
| definitionally, the realm of natural _human_ capacity... it
| pushes what qualifies as superhuman further away, but it
| doesn't mean you've done something superhuman.
| _ZeD_ wrote:
| with my bike I can easily outrun any 100m dasher on the earth.
| yawpitch wrote:
| Sure... and, notwithstanding the apples to oranges comparison
| -- since I can outswim or out stair climb you when you're on
| a bike any day of the week -- that means you're demonstrating
| how fast a human can turn a crank that a human has connected
| to a wheel that a human has realized will transfer traction
| into forward momentum; nothing remotely superhuman has
| occurred, your maximum speed with that implement is still
| _entirely_ limited by your very normal human capabilities.
| verisimi wrote:
| How long till this is fitted with a motor, an e-propeller :)
| gklitz wrote:
| There's already plenty of electric underwater scooters on the
| market. This is novel because it's not electric.
| ramesh31 wrote:
| The real question here is about efficiency, not speed. If this
| does in fact propel divers more efficiently than traditional
| fins, it could be something useful in extending dive times
| without the battery limitations of a sea scooter. Otherwise it's
| just a gimmick.
| yatz wrote:
| Great for special forces, I guess.
| xg15 wrote:
| > _' Underwater bicycle' propels swimmers forward at superhuman
| speed_
|
| so... like a normal bicycle then.
| swader999 wrote:
| Pairing this with some sort of foil board contraption would be
| interesting. Once you get up and out of the water on a foil, it's
| a lot less effort.
| moffkalast wrote:
| Ah, you mean these: https://manta5.com
|
| Yeah, it exists.
| mihaic wrote:
| The rotors should be placed in some fine mesh cage. I don't care
| what the manufacturer says, some idiot is going to cause an
| accident if safety isn't improved.
| wood_spirit wrote:
| It's obscure but there was such a contraption trialled by the
| seals and cia in the 1950s http://www.hisutton.com/CIA_Water-
| Air_1958.html
|
| Here's a pedal powered smuggling submarine from the 1940s
| http://www.hisutton.com/Swiss-Pedal-Powered-Smuggling-Submar...
| pge wrote:
| Interesting that the CIA conclusion for a device very similar
| to the article is "Not recommended for operational use due to
| its discomfort and very slight gain in speed over that of a
| swimmer equipped with fins."
| causal wrote:
| Yeah I think for most uses I would still prefer fins for
| their agility. Cool idea though, and we probably haven't seen
| peak efficiency here.
| RajT88 wrote:
| Peak efficiency probably looks like this:
|
| https://newatlas.com/marine/jetcycle-hydrofoil-pedal-bike/
| causal wrote:
| Nice - yeah that looks more optimal to me.
| aidenn0 wrote:
| 30x the cost though...
| gnicholas wrote:
| That looks absolutely amazing. Super cool that you can
| maintain elevation at less than 6 MPH -- I was expecting
| it to be closer to 10 or 15 MPH.
| RajT88 wrote:
| 6mph is nothing to sneeze at on the water, in terms of
| the power it takes to sustain that kind of speed.
|
| A person paddling can't sustain 6mph for very long, if
| they get there at all.
| Retric wrote:
| World record for a human powered hydrofoil is 21.3 mph.
| https://en.wikipedia.org/wiki/Decavitator 6mph looks a
| lot more reasonable in that context.
| gnicholas wrote:
| Sure, but a person paddling isn't hydrofoiling, right?
| They're using their arms instead of legs and contending
| with tons of additional friction/drag. I see this as
| being akin to bicycling, since it uses the same muscles.
| RajT88 wrote:
| Here's what I am getting at...
|
| https://youtu.be/SDX3Hz2gsas
|
| A guy on one of these doing the minimum speed. He doesn't
| look like he's casually pedaling, no?
|
| It's probably harder to maintain 6mph than you might
| think.
| malfist wrote:
| Eh, it's hard to tell power output from pedaling cadence
| unless it's a fixed gear ratio. Most people pedal between
| 70-100 rpm regardless of the watts they're producing.
| diydsp wrote:
| There are some clues in their body language. they appear
| to be straining. And the pedal movement looks a little
| jerky, as if the load is changing dynamically in relation
| to the effective flywheel/inertia of the system. Spinning
| a higher speeds with less torque is supposedly less
| tiring. So they might want to gear this down a bit and
| include a larger flywheel/inertia. Very impressive device
| tho. Maybe a hybrid approach with a solar panel for
| charging on the beach...
| newaccount74 wrote:
| To me it doesn't look like it they were struggling with
| the physical exertion, but it does seem like they are
| struggling to properly hold on to the boat. It looks like
| the boat suffers from poor ergonomics, and needs some
| proper handles for holding on and steering.
| schiffern wrote:
| >A guy on one of these doing the minimum speed.
|
| Counterintuitively, that probably makes it harder.
|
| With any wing, the faster you go in level flight the
| _less_ drag is caused by lift. This strange fact is
| because moving a large amount of fluid slowly is more
| efficient than moving a small amount of fluid fast, and a
| faster wing can interact with more fluid mass per second
| ( "m dot").
|
| https://en.wikipedia.org/wiki/Lift-
| induced_drag#Calculation_...
|
| Since skin drag increases with speed, adding these two
| drag curves together forms a 'valley' in the overall
| speed-vs-drag curve. Going slower _or_ faster than this
| ideal speed will result in increased energy per mile.
|
| The math is better explained in David MacKay's brilliant
| ebook, ' _Sustainable Energy Without the Hot Air_. '
|
| https://www.withouthotair.com/cC/page_269.shtml
| kitd wrote:
| 6 mph is a gentle paddle in a rowing shell, albeit using
| an additional set of muscles.
| viraptor wrote:
| It depends what they're paddling in. Long, slim racing
| kayak - easy. Short whitewater kayak - impossible.
| tigen wrote:
| Looks like pretty hard work compared to land bikes. You
| never get to coast downhill. I wonder if you can get it
| to surf on waves.
| csours wrote:
| probably should read "trained swimmer with fins"
|
| It can take some time to get used to fins and the motions
| needed. Many more people have ridden a bike
| delfinom wrote:
| Training isnt a problem for government run operations which
| is their context
| csours wrote:
| Yes, but it's not my context.
| noncoml wrote:
| Context of the reply thread...
| loeg wrote:
| Using fins is extremely intuitive for anyone who has swum
| before.
| freeqaz wrote:
| Toss a battery on it though and what does it look like then?
| Perhaps you're able to augment a human's ability to traverse
| longer distances more quickly. That's tech that didn't really
| exist back then!
| thatguy0900 wrote:
| They already have those, seabobs
| londons_explore wrote:
| And it would probably do a decent job of cutting you or
| your friends up when human and the propellor come into
| contact...
| lupusreal wrote:
| "Wartime paddleboards" is not a phrase I ever expected to read.
| dylan604 wrote:
| Brings a new meaning to "Charlie don't surf". At this point
| though, you have to pretty much imagine that the military has
| researched any and every mode/method/means of achieving the
| goals of a mission. I'm sure roller blades and skateboards
| have been considered at some point as well.
| rcruzeiro wrote:
| Not sure about the military, but French police has been
| using rollerblades to patrol the streets of Paris.
| 0xDEADFED5 wrote:
| Taliban rollerbladers:
|
| https://nypost.com/2023/11/15/news/taliban-seen-
| patrolling-k...
| wood_spirit wrote:
| My memory is fuzzy but I think the Australian SAS or SBS made
| raids on the Japanese using paddle boards in the Second World
| War.
|
| It's described in the H I Sutton book, from the website
| above, but I think it's out of print now
| rolph wrote:
| H. L. Hunley (submarine)
|
| https://en.wikipedia.org/wiki/Civil_War_submarine
| soared wrote:
| Seems prime for attaching to a surfboard
| SOLAR_FIELDS wrote:
| I was thinking freediving as it requires less energy than
| flippers though I'm not sure the decreased maneuverability of
| having the thing attached to you would detract from what you
| are wanting to do when freediving. The article does say you can
| dive with it, though the devil is in the details eg how easy is
| it to turn around? I suspice it's not nearly as easy as
| flippers
|
| Another interesting use case would be just tossing one of these
| into a boat that you own, or a kayak or whatever. Basically
| extra insurance to get you back in case your motor dies or you
| get swept out, similar use case as the surfboard
| deegles wrote:
| For those wondering... the tip hooks onto a belt... I had the
| same reaction.
|
| They definitely could make it a lot more clear in the images.
| jononomo wrote:
| Why wasn't this device invented 100 years ago? It's like a
| bicycle for people who need to swim to get around.
| fsiefken wrote:
| I wonder how monofins compare as "swimming" method, similar,
| slower or faster? https://www.youtube.com/watch?v=pBsjtSjQEjM
| moffkalast wrote:
| It certainly has lower energy losses than this geared setup.
| robjan wrote:
| From the looks of the scuba diving video, it looks worse. There's
| way more leg movement and it looks less controlled (and more
| likely to damage corals/kick up sand from the bottom) than slow
| finning.
| margalabargala wrote:
| I'm inclined to agree with you.
|
| That said this certainly has its place. There are lots of use
| cases for wanting to swim more quickly through the water, where
| precise control is less important and where you aren't right
| next to fragile life.
| why_at wrote:
| Given the number of times I've been kicked in the face by
| another person's fins while scuba diving, I wouldn't want to be
| anywhere near someone using one of these.
| FredPret wrote:
| Imagine a pro cycler with one of these
| logtempo wrote:
| on a bike, we don't use hands to propell ourselves for obvious
| reason, why they don't also put a crank for the hands too? it
| double its speed and you can counter balance the legs motion too.
| regularfry wrote:
| Probably attitude control. If your hands are connected to the
| machine, you've got no control surfaces left.
| bschmidt1 wrote:
| Cool invention, kinda like the foil though seems a little
| ridiculous.
|
| Is it really faster than flippers? Didn't seem that quick in the
| video.
| AtlasBarfed wrote:
| Holy shit.
|
| What is apparent when you learn to try to swim is that the
| largest muscles in our body are rendered hugely irrelevant. I
| don't have exact number, but I'd guess at least 95% of potential
| power output of our running-optimized evolutionary muscular-
| skeletal design is wasted in swimming.
|
| Maybe Phelps and others can beat that with decades of training
| from an early age, body shape advantages, long feet, and superior
| flexibility, but I'd guess they buy just 10% more advantage in
| power-> speed conversion from the legs.
|
| Other examples are how much faster you can swim with flippers. I
| would actually like to see good swimmers who train to use full
| scuba flippers vs good swimmers with this bike contraption.
|
| This is hilariously efficient compared to that.
| fnord77 wrote:
| Now just need a way to keep your head out of the water besides
| turning to the sides
| user20180120 wrote:
| Would this device be even better if it has the newer efficient
| propeller design called MX-1 Sharrow Propeller ?
|
| https://www.boatus.com/expert-advice/expert-advice-archive/2...
|
| At the 2020 Miami International Boat Show, Philadelphia-based
| Sharrow Marine introduced the culmination of a seven-year
| research and development project called the MX-1 Sharrow
| Propeller. Unlike every prop that's come before it, rather than
| blades, the MX-1 has loops of metal attached to the hub.
|
| How does this change the dynamic? In a nutshell, much of a prop's
| inefficiency can be blamed on the blade tips, where vortices and
| cavitation (commonly called tip vortex cavitation, or TVC) form,
| creating turbulence and sapping efficiency. Simply put, the loops
| on a Sharrow have no tips. The net result is an efficiency gain
| of between 9% and 15%. But just as important, eliminating the
| cavitation vastly reduces vibrations and noise and makes for a
| smoother, quieter boat ride.
|
| Company president Greg Sharrow tells us that the development of
| the MX-1 can be credited to music videos.
|
| "I was trying to solve the problem of reducing unwanted noise
| from drones while filming live music productions," he says. "I've
| always thought it would be cool to use a drone to get cameras
| closer to subjects and film them from onstage, but you can't use
| drones for music broadcasts because they're too noisy. I knew
| that most of the noise comes from the blade tips and is caused,
| in part, by tip vortices. So, I'd have to find a way to eliminate
| them."
| Chrupiter wrote:
| Would it be a good idea to try on wind turbines?
| EnigmaFlare wrote:
| Utility scale wind turbines are already about 50% efficient
| which is close to the theoretical limit of 59% (Betz limit).
| The loopy blades would be more expensive to manufacture and
| transport so there's a trade-off and it's not obvious that
| efficiency would win.
| AlexandrB wrote:
| Good question! Boat motors spin a lot faster than the
| "Underwater bicycle" propeller would so perhaps it's not as
| beneficial here, but would be interesting to try.
| mrcartmeneses wrote:
| Is that a press release?
| dzhiurgis wrote:
| keep an eye on https://www.youtube.com/@rctestflight - they are
| doing 3d printed prop benchmark/competition and he already
| tested design you mentioned
| nurple wrote:
| I think for water, what you really want is to _breed_
| cavitation, but in a way where the jets created by bubble
| collapse are arranged to face opposite your desired direction
| of motion. Kind of like Astrophage.
| kazinator wrote:
| The male could also use this to improve dispersion of milt over
| the roe laid by the female.
| bandyaboot wrote:
| They should also sell a model that includes a pair of fake feet
| that sort of kick at the surface to complete the illusion that
| you're a freak of nature.
| bambax wrote:
| > _French company Seabike_
|
| They have a .fr domain and a showroom in Cannes, France but the
| company is headquarted in Italy: PARITET SRL, Via
| Giovanni da Cermenate 3, 22063 Cantu (CO) Italy
|
| Also, the French version of the website is riddled with enormous
| errors, like "For traveling light" translated as "Pour voyager
| lumiere", which does not make any sense and isn't even
| grammatically correct (the proper translation would be "Pour
| voyager leger").
|
| The whole thing does not inspire a lot of confidence. Is the
| product real?
| alliao wrote:
| I still am puzzled about the logistics of it, at the very end of
| the video there's a sharp pointy end towards the user... do the
| user shove their private parts between the two shafts...
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