The Underwater Bike....

[Soloist]

What happens when you stop peddling this stupid thing? Notice their legs never stop cranking throughout the video.

 

[Belzelbub]

Well, I guess this is a solution for those divers that can only bicycle kick.

 

[Wibble]

Dere’s dis fing called fizics which comes into play…. As they say in Yorkshire, you get ‘owt for nowt (translation into English: you get nothing for free)

You need energy to overcome drag. Fins are pretty efficient and effective at propelling water backwards and thus the diver forwards, especially when using proper finning techniques. The amount of energy available for propulsion is limited by the horsepower of the diver, but most importantly, how much gas the diver consumes as gas consumption is proportional to the amount energy expended.

For covering long distances, I’ll stick to the (now fixed and dry) scooter.


I reckon the SeaCycle is just because some divers want to play Quidditch. Almost looks like a Nimbus 3000.

 

[dmaziuk]

You need energy to overcome drag. Fins are pretty efficient and effective at propelling water backwards and thus the diver forwards, especially when using proper finning techniques.

I suspect a torpedo-shaped diver with a propeller in the back would do better a human-shaped diver with fins and proper techniques. They just need to add a shell with smaller cross-section and surface area than the diver enclosed within, plus steering and brakes. And then they win your fizzyks.

 

[Sure Squintsalot]

You need energy to overcome drag. Fins are pretty efficient and effective at propelling water backwards and thus the diver forwards, especially when using proper finning techniques.

Fins might be efficiently shaped, but there's nothing efficient about the human kinetics needed to drive them.

FWIW, a lot of money and resources have gone into researching efficient (and fast) human powered propulsion systems for military divers. I recall a two bladed system that looked a lot like a hay baler that propelled a diver at pretty amazing speed despite its size.

I think this SeaBike is pretty inspired, despite the paleolithic propeller design.

 

[tridacna]

They should bundle it with one of these oxygen tanks.

Amazon.com

 

[lexvil]

The Aqueon, and Possible 3rd Generation U/W Swimming Devices | Vintage Scuba Diving Community Forum

Some years ago, I uploaded this image to our website, and it's still there. Right in the center is the Aqueon, and underwater

vintagescuba.proboards.com

Yet fins persist.

 

[johndiver999]

I think it looks pretty cool and I do not claim to remember a whole lot of physics, but I do not necessarily and immediately suspect that the propellor is far less efficient than swim fins.

Seems like a fun toy, but I would want my fins stowed somewhere, just in case. The pedaling stroke looks too short to me for optimized power, but perhaps the drag of knees moving too much would be a negative wrt drag creation.

I know that I have seen human powered submarine races, and I think they all used propellers rather than fins/feet/legs sticking out the rear.

 

[greeniguana]

I would like to see this adapted into something you could bolt to a kayak. Maybe with a shroud.

 

[lexvil]

I would like to see this adapted into something you could bolt to a kayak. Maybe with a shroud.

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