Hey, Spearos.

I just finished the print test for this cute flasher I designed long time ago, and I believe the pro Spearos will love the weight. My guessing is this one will be faster than 0.4ft/s. Good for reef shore dive.

And yes it’s free. File released on Makerworld if you have a 3D printer, try it out, and leave a feedback.

I personally really like this big surface, small body, and easy print.

Most important, I didn’t add any Hydrodynamic control system in this one, it will sink faster.

Enjoy!

AquaJoy Lab

https://preview.redd.it/b9iapmspilyg1.png?width=1290&format=png&auto=webp&s=f8b8d12c5305acd8a7bda8365d6254fb28e9e059

Early flasher designs are often evaluated based on visibility — brightness, reflection, or rotation.

But field testing consistently points to a different limitation.

The limitation was never visibility.
It was control.

https://preview.redd.it/xehxwanxilyg1.jpg?width=940&format=pjpg&auto=webp&s=ca04fc34b3d362249929e10d4b8c6166685bbf5f

V1 OG: motion without control

https://reddit.com/link/1t16yac/video/xtk9xshvilyg1/player

The V1 OG design demonstrated that a 3D printed flasher could generate rotational motion during passive descent.

Tested in both pool and open ocean environments, it showed stable spin and reflective behavior.

However, a key limitation remained:

Descent speed.

At approximately 0.52 ft/s, the flasher exited the diver’s usable window too quickly.
Recovery timing became inconsistent, and the interaction window with fish behavior was limited.

V1 proved that motion was possible.
It did not yet provide control over that motion.

Early attempt: infill-based buoyancy (failed)

https://preview.redd.it/yz54xgn1jlyg1.jpg?width=940&format=pjpg&auto=webp&s=3aae5e8aac62b21152ca593441e7dc48edfd22a3

Initial efforts to reduce descent speed focused on increasing internal air content through print infill adjustments.

This approach proved unreliable.

• Small changes in infill percentage produced large variations in buoyancy
• Results were inconsistent across prints
• Some units failed to sink entirely

The issue was not buoyancy itself, but the lack of control over how it was distributed.

Approximation was not sufficient.

Transition: from percentage to system

The development of V2 began with a shift in approach.

Instead of treating buoyancy as a percentage, it was treated as a spatially controlled parameter.

A simple model was constructed to account for:

• Saltwater density across different environments
• Temperature variation in Southern California waters
• Internal air volume
• Distribution of that volume within the structure

This allowed buoyancy to be positioned, not just increased.

And that positioning directly influenced:

• descent velocity
• body orientation
• stability during motion

This marked the transition from approximation to control.

V2: controlled descent behavior

With the introduction of a controlled internal volume system, V2 achieved a significantly different performance profile.

Average descent speed was reduced to approximately:

👉 0.347 ft/s (Southern California tests)

More importantly, behavior became repeatable.

Compared to V1, V2 introduced:

• A slower and more consistent descent rate
• A longer recovery window
• More stable orientation during drop
• Predictable motion across prints

The flasher no longer simply moved.
It behaved within a controlled range.

Real water validation

Performance was validated through repeated shore diving tests in Southern California.

Each test sequence was recorded continuously:

• release
• water entry
• descent
• bottom contact
• recovery

Example test footage (with time reference):
https://www.instagram.com/p/DPx-WArDiay/

The difference is not just visible in motion, but in time available to act.

On replication and variation

Early open releases led to rapid replication and variation across the space.

Most of these Flasher designs preserved visible features — shape, reflection, but never in a control system with descent rate and rotation actions

But form alone does not define behavior.

Replication tends to preserve geometry,
not the underlying system that controls motion.

What appears similar in air can behave completely differently in water.

Design intent

This work is not centered on appearance.

The original objective was straightforward:

👉 reduce loss by controlling descent

By extending the usable window, recovery becomes more consistent, and the system becomes practical in real dive conditions.

If similar approaches begin to appear more widely,
that outcome still aligns with the original goal.

Beyond form

This is not about ownership of a specific shape.

It is about understanding what actually controls behavior.

The same principles — controlling motion through passive hydrodynamic parameters — are not limited to spearfishing applications.

They can extend to any system where descent and fluid interaction matter, including potential use in oceanographic contexts.

Conclusion

https://preview.redd.it/w0adkkamilyg1.jpg?width=1290&format=pjpg&auto=webp&s=fb55a19b56207cb5e0f602f1cdd2eeee1d8b2923

https://preview.redd.it/3wihaudoilyg1.jpg?width=683&format=pjpg&auto=webp&s=673fea0701749c1703f38cb2ac139f42f9dd1ec0

V1 demonstrated motion.

V2 introduced control.

That is where the system begins to matter.

FL bluewater divers — boat / serious buddy (May 9–10)

Hey,

I’ll be in Florida May 9–10 running a real open-water test session for new Flashers designs.

I’ve done a lot of diving in FL (scuba), but I’m new to spearfishing here — not new to diving, just new to this specific environment.

Looking for someone experienced in bluewater who actually understands offshore conditions and dive safety.

Prefer someone with a boat or already running trips.

This is not a casual fun dive.

We’ll be:

Testing 20–30 unreleased flashers + new holder system

Filming real underwater behavior

Observing fish response in open water

What you get:

A full set of unreleased flashers (not on the market yet)

Dive photos / content from the session

Direct input into future designs

open to split gas or pay charter

I care a lot about safety — only looking for someone solid who knows how to be a real dive buddy.

If you’re already heading offshore that weekend, let’s make it work.

External Disturbance System — Early Hydrodynamic Exploration

Most flashers are designed around visibility.

This one started from a different question:

Can descent itself become the source of motion?

Not added motion.
Not pulled motion.
But motion generated directly from gravity, water interaction, and structure.

The original V1 idea came from a simple physics question: if a flasher already has gravity pulling it down, could wave energy, current variation, and asymmetric drag be used to convert that descent into controlled rotation?
I started with basic assumptions from dynamic reflection and hydrodynamic behavior, then used CAD and 3D printing to turn those assumptions into physical prototypes. After more than a dozen printed test batches, I moved from freshwater pool testing to ocean testing at San Diego Children’s Pool, where the design proved it could self-rotate during descent in real saltwater conditions.

https://preview.redd.it/8j1uthc8jvxg1.png?width=954&format=png&auto=webp&s=7b7709c36d399b3b7c7fd8269ae1a95cb7f6beaf

https://preview.redd.it/44ph9ft8jvxg1.png?width=930&format=png&auto=webp&s=e2bfcc4a85176eaa149a7d4769bbf6bc0d1e4bf1

The Test

Origin of the Design

The initial concept came from a simple physical assumption:

If gravity is already pulling the flasher downward, then wave energy, current variation, and asymmetric drag should be able to convert that vertical descent into rotational behavior.

At the same time, reflection was not treated as a static surface property, but as a dynamic phenomenon — dependent on motion, angle change, and light interaction over time.

The goal was not to “add spin,” but to see whether rotation could emerge naturally from descent.

From there, I used Solidworks to translate these assumptions into physical geometry, and moved quickly into 3D printed prototypes.

Structural Design — External Disturbance System

The V1 structure follows a linear body with externally introduced disturbance.

Core characteristics:

• Linear main body with polygonal cross-section
• External helical fins attached to the surface
• Non-symmetric drag distribution
• Outer pentagonal shell + inner cylindrical core

This design does not rely on internal balance systems.

Instead, all motion is initiated through external hydrodynamic interaction.

Hydrodynamic Behavior

During descent, the structure produces:

• Axial rotation
• Lateral translation (side drift)
• Immediate torque generation from external fins

The important distinction here is:

>

This leads to fast activation in water.

The flasher begins rotating almost immediately after entering descent, with minimal delay.

Performance Characteristics

Field testing showed consistent behavior:

• Fast spin-up
• Strong, direct torque
• High visibility due to continuous angular change

However, the motion profile is also clearly defined:

• Rotation is driven, not emergent
• Movement appears structured and repeatable
• Behavior leans toward mechanical rather than organic

This became an important observation for later iterations.

Dimensions and Practical Constraints

The geometry was not arbitrary.

It was intentionally aligned with real-world use:

• Inner diameter: ~20 mm (based on traditional PVC reference size)
• Length: ~150 mm
• Optimized for comfortable carry on a weight belt

This sizing came directly from field experience, including the loss of a traditional PVC flasher at depth, which set a practical baseline for usability.

Mechanical Integrity

The structural design also focused on durability:

• Polygonal outer shell + cylindrical core
• Compression tested
• Withstood approximately 250 lb adult stepping force

This ensured the product could handle repeated real-world use, including impact, pressure, and handling during dives.

Experimental Methodology

All performance data was collected through field testing, not simulation.

https://reddit.com/link/1sxt9g1/video/30y02exdkvxg1/player

Test Locations

• Catalina Island
• San Diego (including Children’s Pool)

Test Conditions

• Summer season
• Recorded water temperature
• Real ocean current and surge conditions

Test Procedure

Each trial followed a consistent recording method:

• Waterproof camera recorded continuously from release to recovery
• Sequence included:
  • Release
  • Water entry
  • Full descent
  • Bottom contact
  • Retrieval
• Depth verified using dive computer (visually recorded or logged immediately after)

Measurement Method

• Each design tested more than 5 times per depth range
• Depth intervals: ~20 ft, 25 ft, 30 ft

Timing protocol:

• Start: when flasher enters free descent
• End: when flasher reaches bottom

Data processing:

• Fastest and slowest trials removed
• Remaining trials averaged (minimum 3 valid samples)
• Final result expressed in ft/s (feet per second)

Result

• Average descent speed: ~0.52 ft/s

At this rate:

• 20 ft depth ≈ ~38–40 seconds

Why Exclude Outliers

The fastest and slowest trials were removed to reduce variability caused by:

• Release angle differences
• Surface surge and micro-current
• Camera timing inconsistencies

This was not to improve results, but to ensure consistency across repeated tests.

Environmental Consideration

This is not laboratory-controlled data.

It is collected under real ocean conditions.

>

Each dataset includes:

• Location
• Season
• Water temperature
• Depth
• Ocean conditions

All values are recorded and reproducible under similar environments.

Key Observations

The V1 design successfully demonstrated:

• Reliable self-rotation during descent
• Stability in moderate current conditions
• Reduced sensitivity to upwelling due to shorter length
• Immediate activation of motion

Diver feedback consistently favored:

• Faster descent profile
• Strong initial visibility
• Predictable behavior in water

Limitations

Despite strong performance, a critical limitation became clear:

• Motion is externally forced
• Behavior remains predictable
• Rotation lacks variation

The system generates movement, but not behavioral complexity.

It attracts attention.

But it does not consistently create hesitation.

Conclusion

This design represents an early stage in understanding hydrodynamic motion control.

It proved that:

• Descent can generate rotation
• External geometry can drive motion
• Field testing can produce consistent, measurable results

But it also revealed a deeper problem:

Adding disturbance is not the same as controlling behavior.

This realization became the foundation for all later designs.

A customer just released a mini flasher on MakerWorld.

It’s free to download.

Please use real eco-friendly PLA materials when printing.

Not those fake “eco” brands using resin or copied clear plastics.