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'Underwater bicycle' propels swimmers forward at superhuman speed

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Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#141

Post by ninininino »

simonbarker87 wrote: post #48
vitiral wrote: post #37

Earlier quoted context omitted.

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).

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…

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.

Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#142

Post by aidenn0 »

RajT88 wrote: post #111
causal wrote: post #104

Earlier quoted context omitted.

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.

Peak efficiency probably looks like this: https://newatlas.com/marine/jetcycle-hydrofoil-pedal-bike/

30x the cost though...

Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#143

Post by sandworm101 »

lupusreal wrote: post #126
sandworm101 wrote: post #42

Earlier quoted context omitted.

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 adv…

Not sure why you're downvoted. Five minutes for a 500 Free is a pretty typical time for boys on highschool swim teams.

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.

Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#144

Post by aidenn0 »

Milner08 wrote: post #58
Vox_Leone wrote: post #6

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. :)

Is a Monocycle something different to a Unicycle?

You must have missed this: https://news.ycombinator.com/item?id=40080406

Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#145

Post by loeg »

csours wrote: post #123
pge wrote: post #93

Earlier quoted context omitted.

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."

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

Using fins is extremely intuitive for anyone who has swum before.

Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#146

Post by csours »

delfinom wrote: post #133
csours wrote: post #123

Earlier quoted context omitted.

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

Training isnt a problem for government run operations which is their context

Yes, but it's not my context.

Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#147

Post by regularfry »

logtempo wrote: post #138

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.

Probably attitude control. If your hands are connected to the machine, you've got no control surfaces left.

Re: 'Underwater bicycle' propels swimmers forward at superhuman speed

#149

Post by itishappy »

epiccoleman wrote: post #108
simonbarker87 wrote: post #48

Earlier quoted context omitted.

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…

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 breat…

Same here. I can almost float when equipped with a 3mm closed-cell shorty wetsuit (very buoyant), but my legs still pull me vertical...
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