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this post was submitted on 26 Jul 2023
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Bike Commuting
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Yes there are a bunch of pedal-powered boats that are commercially available now. The one in the picture looks like it's driving a giant paddle wheel. There are issues with paddle wheels, like their large size, weight, noise and efficiency. They also don't deal with large waves very well and can be damaged relatively easily. You can still find these often for rent in touristy lake destinations. The paddle wheels are typically enclosed underneath the boat so they're safer, but they're still pretty noisy and inefficient.
You can find modern pedal-powered boats that spin a propeller in the water, just like you find on most watercraft with engines. Propellers solve pretty much all these problems, which is why they are the standard way of propelling watercraft today.
There's also a fun pedal-driven design from Hobie that pushes underwater fins back and forth. This emulates how many fish swim and is supposed to be even more efficient than propellers.
I've seen a test of the Hobie design in a race with pedal powered designs. IIRC I don't think it faired very well.
You got me curious, so I looked up some comparisons. They all seem to show the Hobie favorably. The Hobie appears faster and more efficient than the propellers I saw. Also much more torque because the fins are so much larger than the propellers, so you get better acceleration from a stop.
https://www.youtube.com/watch?v=k3ORsW2sn4Q
I couldn't find perfect apples to apples comparisons, but that video seemed to illustrate the general comparison.
That Hobie propulsion system looks interesting