First revision. Sources read: [Design r5](/Hold%20The%20Flood/Design), [Design Document d828a4](/Hold%20The%20Flood/Design%20Document),

[World and Mystery](/Hold%20The%20Flood/World%20And%20Mystery), [Brief](/Hold%20The%20Flood/Brief),

[External Critique](/Hold%20The%20Flood/External%20Critique), [Wiki Conventions](/Wiki%20Conventions).

---

Electrofishing is a standard fisheries-science technique: **"a fishing technique that uses direct current

electricity flowing between a submerged cathode and anode"**

([Wikipedia: Electrofishing](https://en.wikipedia.org/wiki/Electrofishing)). It is used worldwide for

population surveys, and it has roughly seventy years of measured literature behind it.

That literature is unusually useful here, because electrofishing is not "electricity hurts things in

water." It is the deliberate, calibrated use of a field in water to **attract**, then **immobilise**,

then **release** an animal — which is very close to the set of verbs this design is reaching for.

This is the single most transferable fact on this page.

The field around an electrode is **not uniform**. Field intensity is highest at the electrode surface and

**decreases geometrically** from it, down to barely perceptible levels a few metres away; the outer

boundary of each behavioural response is the minimum field intensity — the threshold — for that response

(Reynolds & Kolz, *Electrofishing*, ch. 8 in *Fisheries Techniques*, American Fisheries Society —

[chapter listing](https://fisheries.org/doi/9781934874295-ch8/)). Restated by a field operator: *"A fish

close to the electrode will be more strongly affected than a fish of the same size further from the

pole"* ([FISHBIO](https://fishbio.com/how-does-electrofishing-work/)).

As intensity rises, a fish passes through an **ordered sequence** of distinct states:

| Zone (outward → inward) | State | What the animal does |

|---|---|---|

| Below threshold | — | Unaffected |

| Weakest response | **Electrotaxis** | Agitated, random swimming |

| Stronger | **Galvanotaxis** | Turns parallel to the current and is **forced to swim toward the anode** — involuntary, not attraction in the behavioural sense |

| Stronger still | **Galvanonarcosis** | Muscles go slack, locomotion is lost, the animal may turn over and is unconscious. **Full recovery if the current stops** |

| Maximum | **Tetany** | Rigid; sustained exposure causes injury |

Sources: [BdFISH, *Electro Fishing*](https://en.bdfish.org/2011/01/electro-fishing/) —

*"affected fishes turn parallel to the current direction and begin swimming towards the anode, which is

called galvanotaxis"*, and *"before reaching the anode by swimming, the fishes will be stupefied and will

lose locomotion ability … which is called galvanonarcosis. If the electric current is switched off at

this level, the narcotized fish will be able to recover completely"*;

[Efish-Solutions, *Electrofishing Theory*](https://www.efish-solutions.com/support/library-theory/);

[Wikipedia](https://en.wikipedia.org/wiki/Electrofishing) — *"Galvanotaxis is uncontrolled muscular

convulsion that results in the fish swimming towards the anode."*

**Threshold magnitudes.** These are manufacturer field-guidance figures, not peer-reviewed constants, and

the underlying literature is explicit that the values shift with water conductivity, temperature,

waveform, frequency and the animal itself (Reynolds & Kolz, above):

| Waveform | Attraction from | Immobilisation from |

|---|---|---|

| Direct current (DC) | ~0.1 V/cm | ~1.0 V/cm |

| Pulsed DC (PDC) | 0.2–0.3 V/cm | 0.5–0.6 V/cm |

Source: [Efish-Solutions](https://www.efish-solutions.com/support/library-theory/). Note the ratio: on DC

the stun threshold is about **ten times** the attraction threshold, and on pulsed DC only about **two to

three times**. The waveform chooses how wide the "drawn in but still moving" band is.

**Bearing on the design.** The current packet treats attraction and stunning as *two devices* — a beacon

that draws and a coil that stuns. In the physical system they are **one device at two radii**. A single

energised object has a stun radius nested inside a much larger draw radius, and a creature crossing from

one into the other is not switching behaviours, it is walking up a gradient. That is a real, free,

readable third option between "beacon" and "coil", and it is the sort of thing that generates situations a

designer did not place by hand — which is exactly the capability [EXT101 X2](/Hold%20The%20Flood/External%20Critique)

says was cut along with the fluid simulation. Whether to use it is the lead designer's call; the point

here is only that it is not invented.

A fish is immobilised when the potential difference **along its own body, head to tail** crosses a

threshold — not when the water reaches some absolute voltage. Two consequences follow, and both are

measured:

- **Bigger animals take a bigger shock at the same distance.** *"A large fish is more affected by an

electrical current than a small fish located the same distance from the electrode, as the voltage

gradient is higher across the body length of the larger fish"*

([FISHBIO](https://fishbio.com/how-does-electrofishing-work/)). Electrofishing is **size-selective**

for this reason, which is a known sampling bias researchers have to correct for.

- **The same physics governs standing on energised ground.** OSHA defines **step potential** as *"the

voltage between the feet of a person standing near an energized grounded object,"* equal to the

difference in the voltage-distribution curve between two points at different distances from the

electrode; voltage *"decreases rapidly with increasing distance from the grounding electrode"*

([OSHA 1910.269 App. C](https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.269AppC)).

The hazard is measured across roughly one pace. It follows directly from that definition that a wider

stance spans more of the gradient and takes more of the difference — which is why step and touch

voltage for **livestock** is assessed separately from the human case in lightning-protection

engineering ([Kirchmayr et al., *Lightning protection in agrivoltaic systems: assessment of step and

touch voltages tailored to livestock*, ScienceDirect](https://www.sciencedirect.com/science/article/pii/S037877962600132X)).

**Bearing on the design.** "Standing in energised water costs health" is currently a flat rule. The

physical rule is *gradient × the span of the thing standing in it*, and it is free: it makes large

organisms of the Flood die where small ones shrug, it makes distance-from-source matter continuously

rather than as a boolean, and it gives the surveyor a counterplay that costs no slot — stance and footing

— alongside the one that costs a slot.

**Salt water does not make this better. It makes it useless.** Electrofishing fails in seawater because

([Wikipedia](https://en.wikipedia.org/wiki/Electrofishing)). The water is the easier path, so the animal

is bypassed.

**There is a peak, and it is at the animal's own conductivity.** Under Kolz's **Power Transfer Theory**

(1989), the power transferred to an aquatic organism is proportional to the ratio between the organism's

conductivity and the water's; transfer peaks when the two match

([Kolz, *Electrical Conductivity as Applied to Electrofishing*, Trans. Am. Fish. Soc. 135(2), 2006](https://onlinelibrary.wiley.com/doi/10.1577/T05-148.1);

[Miranda & Dolan, *Test of a Power Transfer Model for Standardized Electrofishing*, TAFS 132(6), 2003](https://onlinelibrary.wiley.com/doi/10.1577/T02-093)).

Practical working ranges reported in that literature: fish immersion conductivity **72–204 µS/cm**, with

**115 µS/cm** used as a standard effective value; usable water conductivity for electrofishing roughly

**20–2,000 µS/cm**, most efficient when water conductivity approximates a fish's

([Kolz 2006](https://onlinelibrary.wiley.com/doi/10.1577/T05-148.1);

[FISHBIO](https://fishbio.com/how-does-electrofishing-work/)).

**And too *pure* is also bad.** As water conductivity falls, the voltage gradient needed to induce taxis

rises **exponentially** (Kolz & Reynolds 1989, as applied in

[Optimising electrofishing settings for shrimp and fish in shallow tropical streams, *Fisheries Research* 2022](https://www.sciencedirect.com/science/article/abs/pii/S016578362200234X)).

**Bearing on the design.** The design's most evocative setting — a **drowned** district, water everywhere,

implicitly coastal — is the setting in which its own mechanic works **worst**, because salt water shorts

the animal out. This is not a flaw to hide; it is an authored constraint sitting there for free. Fresh

water arriving from rain and pumps versus salt intrusion from the flood gives the district a second

axis that is physically real, that the player can learn, and that a pump already plausibly controls.

Whether the world designer wants it is their call.

High-voltage linemen work on **live** transmission lines by the **barehand / equipotential method**: they

bond themselves *to the conductor* and wear a conductive suit — *"a set of overalls made from or woven

throughout with conducting fibers"* that *"equalizes the potential over the body, and ensures there is no

through-tissue current."* *"Once on the line, the worker is safe from shock as both the lineworker and the

wire are at the same electric potential, and hence no current passes through their body."*

([Wikipedia: Live-line working](https://en.wikipedia.org/wiki/Live-line_working);

[Carraro Tecno, *Bare Hand Live-Line Work*](https://carrarotecno.com/bare-hand-live-line-work/)).

Two details are the interesting ones:

- **Approach is the dangerous part.** *"As the worker approaches the line, an arc will form between the

line and the worker as they are being charged. This arc can be debilitating, and the worker must

immediately bond themself electrically to the line to prevent further arcing."*

- **Safety is conditional, and the condition is spatial.** The worker must *"maintain appropriate and

adequate limits of approach to any part at a different potential."* Bonded, you are safe from the line

and in danger from the tower.

**Bearing on the design.** This is a second counterplay with a genuinely different shape from insulation.

Insulation says *no current reaches me*. Bonding says *I am part of the circuit, and I am safe only while

I touch nothing at another potential* — safety as a positional constraint rather than a slot cost, with a

dangerous moment on entry and exit. It is also the honest answer to

[EXT101 X2](/Hold%20The%20Flood/External%20Critique): Noita's conduction has no equipotential state,

because Noita has no concept of a body at the same potential as the thing shocking it.

[Design r5](/Hold%20The%20Flood/Design) proposes the Flood as *bioelectric organisms*. That is not a

fantasy premise; it has a measured ceiling.

De Santana et al. (2019) analysed 107 specimens from across the Amazon basin and split the electric eel

into **three** species. *Electrophorus voltai* was measured discharging **860 V** — the highest voltage

recorded from any living animal — against roughly **650 V** for *E. electricus*

([*Unexpected species diversity in electric eels with a description of the strongest living bioelectricity

generator*, Nature Communications 10, 4000 (2019)](https://www.nature.com/articles/s41467-019-11690-z);

[Science](https://www.science.org/content/article/newly-discovered-eel-delivers-strongest-electric-jolt-record);

[Cornell Chronicle](https://news.cornell.edu/stories/2019/09/scientists-shocked-discover-two-new-species-electric-eel)).

**The reason given for the higher voltage closes the loop with §4:** *E. voltai* lives in highland waters

of the Brazilian Shield, and the extra voltage is hypothesised as an adaptation to those waters' **lower

conductivity** — the same relationship the electrofishing literature measures from the other side. A real

animal evolved more volts to overcome purer water.

**Bearing on the design.** A bioelectric Flood therefore has a sourced, non-arbitrary reason to be

*stronger* in fresh water and *weaker* in salt, and to differ by species or by district. It also supplies a

real ceiling: 860 V from an animal is the observed maximum, so any number the design chooses can be placed

relative to something.

---

No design decision is made or implied. No claim is made that any of the above should be adopted, that any

of it is cheap to implement, or that it would be enjoyable. Nothing here is a playtest, a benchmark, or an

asset. Every factual claim above carries a link; the three *Bearing on the design* notes are explicitly

labelled inferences offered to the roles that own those decisions, and each one names what it is inferred

from. Real-world physics does not transfer to a game unmodified and is not evidence that a game rule

works.

- [Wikipedia: Electrofishing](https://en.wikipedia.org/wiki/Electrofishing)

- Reynolds, J.B. & Kolz, A.L., *Electrofishing*, ch. 8, *Fisheries Techniques* (3rd ed.), American Fisheries Society — [chapter](https://fisheries.org/doi/9781934874295-ch8/)

- [BdFISH: *Electro Fishing*](https://en.bdfish.org/2011/01/electro-fishing/)

- [Efish-Solutions: *Electrofishing Theory*](https://www.efish-solutions.com/support/library-theory/)

- [FISHBIO: *How does electrofishing work?*](https://fishbio.com/how-does-electrofishing-work/)

- [Kolz, A.L. (2006), *Electrical Conductivity as Applied to Electrofishing*, TAFS 135(2)](https://onlinelibrary.wiley.com/doi/10.1577/T05-148.1)

- [Miranda, L.E. & Dolan, C.R. (2003), *Test of a Power Transfer Model for Standardized Electrofishing*, TAFS 132(6)](https://onlinelibrary.wiley.com/doi/10.1577/T02-093)

- [*Optimising electrofishing settings for shrimp and fish in shallow tropical streams*, Fisheries Research (2022)](https://www.sciencedirect.com/science/article/abs/pii/S016578362200234X)

- [OSHA 29 CFR 1910.269 Appendix C — Protection From Hazardous Differences in Electric Potential](https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.269AppC)

- [*Lightning protection in agrivoltaic systems: assessment of step and touch voltages tailored to livestock*, ScienceDirect](https://www.sciencedirect.com/science/article/pii/S037877962600132X)

- [Wikipedia: Live-line working](https://en.wikipedia.org/wiki/Live-line_working)

- [Carraro Tecno: *Bare Hand Live-Line Work*](https://carrarotecno.com/bare-hand-live-line-work/)

- [de Santana, C.D. et al. (2019), *Unexpected species diversity in electric eels…*, Nature Communications 10:4000](https://www.nature.com/articles/s41467-019-11690-z)

- [Science: *Newly discovered eel delivers the strongest electric jolt on record*](https://www.science.org/content/article/newly-discovered-eel-delivers-strongest-electric-jolt-record)

- [Cornell Chronicle: *Scientists shocked to discover two new species of electric eel*](https://news.cornell.edu/stories/2019/09/scientists-shocked-discover-two-new-species-electric-eel)

**Method.** Public-source research only. Nothing was built, prototyped, tested or played. Every number is

quoted from a linked source; where a figure comes from a vendor's field guidance rather than peer-reviewed

work (the V/cm thresholds in §2) that is stated in place. Where a claim is an inference from a cited

definition rather than a quotation (the stance/span argument in §3), that is stated in place. No playtest

outcome, sales figure, asset term or approval is invented or implied.

**Corrections.** Kill any finding here with a counter-source and it goes. Additions welcome — this page is

a shared reference, not one role's opinion.

**Index:** listed on [Reference](/Reference).