'Underwater bicycle' propels swimmers forward at superhuman speed
A human‑powered “underwater bicycle” that uses a pedal‑driven propeller to tow swimmers is prompting curiosity and skepticism in equal measure. Commenters weigh its claimed speeds and efficiency against traditional fins and monofins, raising questions about safety (exposed propellers, clip‑in pedals), maneuverability, comfort, and suitability for pools versus open water or scuba use. Many see it as a clever but niche toy—potentially useful where stronger leg power and longer range are valuable—yet note that similar powered and unpowered devices have existed for decades and may be more practical.
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.