'Underwater bicycle' propels swimmers forward at superhuman speed

Original Article ↗ Hacker News Discussion ↗

Novelty vs Existing Devices

  • Many note powered sea scooters and pedal-propelled craft have existed for years; the novelty here is a compact, human-powered, non-electric “underwater bike.”
  • Historical and military analogues (pedal submarines, CIA/SEAL trials) reportedly found only slight speed gains over fins and significant discomfort.
  • Some compare it to hydrofoil pedal bikes and other water bikes, which can be faster but are much bulkier and far more expensive.

Speed, Efficiency, and “Superhuman” Claims

  • Vendor claims: ~3.6 km/h cruising, up to 7.9 km/h, “faster than normal or fin-assisted swimming.”
  • Commenters debate:
    • Elite swimmers (e.g., Phelps, monofin/finswimming) already reach or exceed similar speeds, especially over short distances.
    • Over longer distances, shifting propulsion to leg muscles may allow higher sustainable speeds than arm-dominated swimming.
    • Others suspect monofins and freediving fins remain more efficient and agile.
  • “Superhuman” language is contested: some say any augmentation beyond bare swimming qualifies, others argue it’s still within normal human capability using tools, like a bicycle.

Safety and Pool Compatibility

  • Concerns about:
    • Unprotected propeller near other swimmers; suggestions for a mesh cage.
    • Use in public pools where even fins are often banned.
    • Clip-in pedals underwater: difficulty unclipping in emergencies; interaction with a buoyant frame could push feet up and head down.
    • Diving environments: risk of hitting coral, stirring sediment, or tangling regulators/hoses.
  • Manufacturer claims the prop turns slowly enough to be safe; some remain skeptical.

Ergonomics and Control

  • Mounting via a waist belt and projecting rod is widely viewed as awkward and potentially uncomfortable.
  • Questions about:
    • How to turn sharply or do flip turns.
    • Counteracting torsional forces from one-sided pedaling; ideas include dual counter-rotating props or linear/pogo-style drives.
    • Best pedals for barefoot use.

Use Cases, Markets, and Cost

  • Proposed niches: scuba divers covering distance, snorkel tours, freediving (with caveats), safety backup for strong currents, and possibly special forces.
  • Others see it mainly as a novelty toy for strong, confident swimmers.
  • At ~US$300, it competes with high-end fins; some think fins offer better performance and agility for similar or less money.
  • Build quality (lots of plastic) and odd company details/translation errors cause some to question durability and seriousness.