What Depths Accept

DEPARTMENT OF THE NAVY

OFFICE OF UNDERSEA WARFARE ANALYSIS

PACIFIC FLEET

CLASSIFICATION: TOP SECRET // NOFORN

SUBJECT: After-Action Assessment — Littoral Ordnance Field

(Uncharted)

REFERENCE: Tasking Order 7-13-Λ

LOCATION: Northern California Offshore Shelf

AUTHOR: Lt. Cmdr. ████████ ██████, USN

DATE: █████████

1. PURPOSE

This report documents observations, procedural outcomes, and unresolved anomalies encountered during the Navy-led assessment of an uncharted submerged ordnance field discovered during civilian hydrographic survey operations. The intent is to provide a factual account suitable for higher-level evaluation. Speculation has been minimized per guidance, though complete exclusion was not possible.

2. BACKGROUND

In ████████ civilian surveyors reported magnetic interference and unexplained acoustic returns approximately ██ nautical miles offshore. Initial review suggested legacy ordnance consistent with Cold War–era defensive emplacement, though no corresponding archival deployment records were found in Naval History and Heritage Command databases.

Given proximity to shipping lanes and offshore infrastructure, Pacific Fleet authorized a limited investigation using a mixed team of Navy EOD divers and civilian contractors under Navy supervision.

The working assumption at deployment was incomplete charting rather than misplacement.

That assumption is no longer supported.

3. ENVIRONMENTAL CONDITIONS

The operating area presents as unremarkable coastal shelf. Depth gradients are consistent with regional geology, except within a localized depression roughly ███ meters in diameter. This depression is not associated with known faulting, scouring, or sediment collapse.

Water conditions throughout the operation were stable. Visibility varied but remained within operational norms. There were no storms, seismic events, or anomalous currents recorded during the relevant period.

Despite this, multiple divers independently reported difficulty assessing distance and scale once below approximately 90 feet. This was initially attributed to light attenuation and particulate density. Subsequent review suggests this explanation is insufficient.

4. ORDNANCE DESCRIPTION

A total of ██ discrete mines were positively identified.

They resemble modified Mark VI contact mines, though none fully match archival schematics. Corrosion patterns indicate long-term emplacement, but material integrity exceeds expected degradation for their apparent age.

Notable deviations:

Mine spacing does not conform to defensive grid doctrine.

Orientation trends inward toward the central depression.

Anchor chains appear partially embedded in sediment, as though placed prior to sediment accumulation rather than dragged into position.

Trigger assemblies include components not standard to the period suggested by hull construction.

These deviations were documented photographically and via ROV feed. Analysis remains ongoing.

5. FAUNA INTERACTION

Large predatory fish—primarily sharks—were present during every dive.

This is not remarkable in isolation. What is notable is their behavior.

The animals did not display territorial aggression, curiosity, or feeding response. Instead, they maintained consistent spacing relative to the ordnance field and avoided the central depression entirely. Their movement patterns were synchronized beyond what is typically observed in opportunistic grouping.

On three occasions, sharks altered orientation in direct response to diver depth changes, not lateral movement. This was confirmed by video review.

The animals behaved less like scavengers and more like passive monitors.

No attempts were made to deter them. No deterrence would have changed the situation.

5A. FAUNA OBSERVATION – DETAILED

Shark Population:

Throughout all operational dives (n=7), large predatory elasmobranchs were consistently present. Species identification via video review and morphological analysis includes:

Carcharodon carcharias (Great White) – 4–6 individuals observed per dive

Carcharhinus obscurus (Dusky Shark) – 3–5 individuals

Isurus oxyrinchus (Shortfin Mako) – 1–2 individuals, highly mobile

Behavioral Anomalies:

Spatial Consistency:

Sharks maintained uniform radial spacing around the ordnance field, roughly 8–12 meters from the nearest mine.

Deviations occurred only when an ascent or descent intersected a perceived threshold, after which spacing normalized within seconds.

Central Depression Avoidance:

All observed sharks avoided the central depression entirely.

Video overlays indicate avoidance is not random: edges of the depression were circumscribed precisely, forming an effective “no-go zone.”

Sharks did not engage with objects or disturbances introduced within this zone (e.g., small ROVs, test buoys).

Synchronized Orientation:

Multiple sharks simultaneously adjusted pitch, yaw, and body angle in response to diver depth changes, even when lateral movement was absent.

Adjustments occurred within a 2–3 second window across individuals separated by 10–15 meters.

Patterns were reproducible: repeated depth change sequences triggered identical responses.

Motion Suppression & Station-Keeping:

Sharks often suspended normal locomotion while maintaining orientation, using minimal tail beats.

The animals appeared to hover, conserving energy yet maintaining precise alignment relative to the ordnance.

Observed primarily when low-frequency hydroacoustic signals intensified.

Non-Feeding Response:

Despite diver activity and baited ROV presence, no predatory behavior was observed.

Sharks ignored suspended food stimuli unless presented outside the radial boundary.

Feeding response resumed only after leaving the field, indicating behavioral suppression is site-specific.

Possible Mechanosensory Detection:

The rapid, coordinated adjustments to vertical motion suggest sensitivity to low-frequency hydrodynamic changes.

Likely mediated via lateral line system and ampullae of Lorenzini; response latency is inconsistent with standard predation or schooling behavior.

Interpretation:

Sharks do not act as passive wildlife. Their presence is functional and procedural relative to the mine field.

They may serve as a bio-monitoring layer, detecting vertical displacement or pressure anomalies.

Their avoidance of the central depression implies recognition of a zone of significance, though no known biological rationale accounts for this behavior.

The predictable nature of their positioning, orientation, and motion suppression suggests long-term conditioning, evolutionary adaptation, or external stimulus synchronization beyond ordinary environmental cues.

Operational Considerations:

No deterrent devices (sound, light, electrical) were effective in altering shark positioning.

Divers’ safety protocols must account for precise radial movement patterns; inadvertent breach of spacing may trigger coordinated response.

Observed behavior could compromise disarmament operations: interference with the field alters shark distribution, which correlates with measurable changes in hydroacoustic activity.

Conclusion:

The elasmobranch presence is integral to the ordnance field system’s functionality. Their behavior is neither aggressive nor defensive in conventional terms but appears purpose-driven, effectively maintaining perimeter integrity and providing indirect feedback to the system. Continued observation is recommended, with non-intrusive monitoring prioritized to preserve both diver safety and system integrity.

6. ACOUSTIC PHENOMENA

Hydrophones detected low-frequency signals between 7–10 Hz originating from beneath the depression.

These signals do not correspond to:

Known marine mammal vocalizations

Seismic background noise

Shipping or industrial activity

Submarine traffic

The signal is intermittent but rhythmic. It is best described as a pressure modulation rather than a sound in the conventional sense.

Divers did not “hear” it. They reported feeling it through suit contact points and bone conduction. This distinction matters.

When the signal intensified, divers experienced involuntary equalization responses, disorientation, and—most concerning—behavioral hesitation inconsistent with stress response profiles.

No panic was recorded. Instead, divers delayed actions they had already committed to performing.

7. DISARMAMENT ATTEMPTS

Two controlled attempts were made to neutralize selected mines.

In both cases, no explosive detonation occurred. Instead, divers reported sudden pressure displacement localized around the mine body, followed by immediate changes in acoustic readings.

It is the assessment of the undersigned that the mines are not configured primarily as destructive devices.

Their function appears to be responsive, not preventative.

In lay terms: they react not to intrusion, but to movement in a specific direction.

Specifically—upward movement originating from below the mine field.

8. INCIDENT OF ████████

During the third operational phase, authorization was granted to remove a single mine for surface analysis.

The mine was successfully detached and lifted.

At approximately ██ feet during ascent, the mine detonated.

This detonation did not propagate outward in the expected radial pattern. Instrumentation indicates a directional pressure wave oriented downward toward the seabed.

Immediately following the event:

The low-frequency signal ceased.

All observed sharks dispersed.

The central depression registered a temporary pressure spike consistent with volumetric displacement.

No crater was formed.

No debris plume was observed.

It is unclear what received the force of the detonation.

9. ANALYSIS

The mine field does not function as an area denial weapon.

It functions as a depth-regulated system.

The most consistent interpretation, based on available data, is that the mines serve one of two purposes:

To prevent the slow ascent of a large object or mass from below the seabed.

To provide controlled pressure stimulation at specific intervals.

These interpretations are not mutually exclusive.

It is worth noting that slow ascent is a condition rarely addressed in naval doctrine. Most threats are assumed to move quickly or catastrophically.

Whatever this system was designed for does neither.

10. HISTORICAL REVIEW

No official record explains the emplacement.

However, partial matches were found in classified Cold War research into undersea acoustics, pressure signaling, and non-kinetic deterrence. Several programs remain heavily redacted even within TS channels.

One declassified memorandum (███/███) references “persistent undersea anomalies requiring containment rather than engagement.” No further elaboration is provided.

11. CONCLUSIONS

I will state this as carefully as possible.

The ordnance field appears to be performing its intended function.

Interference degraded that function.

Local actors—specifically civilian fishermen—appear to have adopted informal practices that indirectly support system stability (e.g., deliberate diversion of predatory fauna).

Whether this knowledge was inherited, inferred, or coincidental cannot be determined.

12. RECOMMENDATIONS

Suspend all further disarmament operations.

Reclassify the site from “hazard” to “containment.”

Restrict civilian diving and survey activity without explanation.

Do not remove additional mines.

This recommendation is not made lightly.

But the system has been in place for decades.

We arrived, attempted to make sense of it, and immediately caused measurable change.

That should be treated as a warning.

13. FINAL NOTE (UNOFFICIAL, RETAINED PER LEGAL)

There is an assumption in undersea warfare that threats come from outside—foreign navies, hostile actors, unknown vehicles.

This system does not face outward.

It faces down.

And it has been very patient.

Adjacent files.

The Private Notes of Captain Patteron USN. VF-51, Fighter Squadron 51. ‘Seahawks’:

I have spent my career trusting instruments, charts, and physics. Today, none of that mattered. None of it.

Ejection from 3,200 feet was textbook, if you ignore that my parachute somehow felt like it was pulling down faster than gravity, and the water surface refused to behave. The depression came into view—a perfect black circle carved into the shelf—and my first thought was: sonar glitch. That’s what I tell myself now.

Then the sharks appeared. Not “oh, hey, some circling predators” sharks. These things moved like they were in formation drills—radial, precise, unblinking. I could feel them before I even hit the water. I’ve chased and counted more sharks in training exercises than I care to admit. Never like this. Never this… aware.

I swear I could hear my own heartbeat over the water. Time dilated. Distance distorted. I know I’m not hallucinating. I’m a pilot. A logical, trained, rational operator. And yet… something below this shelf is telling me otherwise.

By the time I drifted toward the cove, I should have been afraid of the people who met me. They were lightly armed, certainly capable of doing damage if I tried anything stupid, but that wasn’t what scared me. It was the certainty in their movement. They gestured at the sharks, the water, the depression itself. “Fast movement up is bad,” they said. Not in words—actions. Everything deliberate.

I wanted to argue. My brain kept firing off facts, formulas, whatever Navy bullshit I thought would explain this. But my gut… my gut was screaming something else. Something older. Louder. It wasn’t fear. Not exactly. It was like the universe was smirking at me and saying, you don’t get to be the smartest guy here. I’ve spent my life trusting instruments, calculations, rules. Today? All of that got laughed at by water and teeth.

My eyes locked on to the weapons: copper points, small cartridges, primitive arrows. A laughable arsenal if I were back on the flight deck. And yet they hadn’t failed by accident—they failed because they couldn’t stop it. Something down there ignores bullets, ignores pointy metal, ignores every goddamn law of physics I understand.

I had a choice: retreat or comply. Pride screamed “retreat,” but curiosity—scientific, analytical, ego-fueled curiosity—won.

The platform was a mess of driftwood, rope, and carved timber. Precision everywhere, in contradiction to the apparent chaos. Small effigies were arranged: fish bones, arrows, copper wire. I counted the seconds in my head, trying to rationalize the slow, ritualized lowering of the volunteer. I tried to measure everything. I tried to impose my order on it. Failed.

Sharks circled. I noted angles, spacing, movement rhythms. Even tried to predict their shifts. I failed.

The young man—socially marked, maybe already dying in a sense I can’t quantify—was lowered slowly into the depression. Every inch deliberate. I timed it. Measured pulse against hydroacoustic vibrations. Checked alignment of sharks. Thought I was being rational.

The water pressed in. I literally felt my own logic unravel. My instruments couldn’t explain it. My mind argued with itself. “You are overreacting,” I said. “Physics will save you.” Physics didn’t. The depression didn’t. The hunger… maw… below… wasn’t a thing I could calculate.

I realized I was the variable now. The observer effect is real, and I’m terrified.

Jonah. I couldn’t stop the sunday school behemoth, the way he was swallowed whole, trapped inside something massive and incomprehensible, completely at the mercy of forces he couldn’t control. I scoffed at it at first, as if comparing me—a trained, logical, rational Navy officer—to a biblical story about a guy who ran from God was some kind of cosmic joke. Jonah survived by submission.

By lying still, by letting the whale carry him, by giving up. Submission. I don’t do that. I never do that. I solve problems. I take things apart, map them, fix them, dominate them. That’s my life. That’s who I am.

And yet… here I am. Swallowed. Not by a whale, not literally, but by this depression, by whatever sits below it. Slowly. Methodically. The water presses in, heavier than physics says it should, and I realize I can’t chart it. I can’t predict it. Every instinct I have to move fast, to grab control, to assert dominance, is exactly what they warned against. Fast is dangerous. I scoffed at superstition, but now I feel like Jonah, trapped in a space that doesn’t respond to logic, waiting for the currents and the predators and the ritual to decide whether I live or die.

And the kicker? Jonah wasn’t just swallowed—he had time to think. Time to understand the limits of his ego. Time to accept that some forces are bigger than him. I feel the same. My pride is screaming, my brain is whirring, but it’s useless against the system here.

My ego, which has carried me through every mission, every storm, every near-impossible rescue, is irrelevant. The water has no respect for it. The sharks don’t care. The depression doesn’t care. And like Jonah, I’m learning that sometimes survival isn’t about solving the problem—it’s about enduring it, riding the currents, letting the system work around you.

The sharks weren’t predators. They were guides, guardians, instruments of a system I don’t understand. They watched the volunteer descend, then they watched me, and I realized my ego—my pride in being rational—was meaningless here.

I’m the guy who charts storms, who predicts currents, who reads the ocean like a book. Today, the ocean read me. And it disagreed with my conclusions.

The copper arrows, cartridges, driftwood projectiles—they make noise. They splash. They leave dents. They accomplish nothing. I tried to rationalize why. I tried to simulate the physics. I failed. No equation, no model, no training predicted what happened when the volunteer descended: pressure pulses, hydroacoustic shifts, synchronized shark movement.

Weapons are irrelevant. Ego is irrelevant. Only compliance matters. And I hate that. I hate that it works.

I was allowed to leave. Slowly. Carefully. Every inch upward measured. Sharks maintained alignment. Hydroacoustic pulses decreased. The volunteer was gone. Everything “reset.”

I am alive. I am unhurt. I am rational. I am lying to myself if I say this makes sense.

I have logs, instruments, and diagrams to prove I observed nothing anomalous—yet I know it exists. I felt it.

Hours of government training failed me today. Observation alone cannot explain it. I am trained, disciplined, analytical—and I am terrified.

I keep replaying it in my head, trying to make sense of it, but there are rules here that no amount of training prepares you for. Don’t ascend too fast. Not even a little—every sudden move feels like it’s testing you, probing for weakness.

The sharks… they’re not threats, not really; they’re part of something bigger, a system I barely understand and that doesn’t give a damn about me. And the weapons—forget it. Bullets, arrows, anything you think will work, it doesn’t matter. The only way to survive is slow, deliberate compliance, careful movement, measured offerings.

Jonah was right. Pride is swallowed first, and I’m starting to feel like I’ve been chewing on that lesson for the last hour, bitter and unavoidable.

They told me to keep my mouth shut. Not angrily. Not threatening. Just the way you tell someone the rules of gravity. You lose your pension for talking nonsense about less than this. I know how that sentence works. I’ve seen men disappear into early retirement over worse wording than “ritual” or “sacrifice.”

I’ve got kids who need college money. A wife who’s been talking about Maui for years like it’s a promise I owe her. I nod. I sign. I shut up.

But I don’t think I’ll ever look at the Pacific the same way again. Not the way it stretches out so calm and blue, pretending it’s empty.

I used to see water and distance and math. Now I see depth and patience and something that knows exactly how long it can wait. I don’t dream about it—not really—but sometimes I wake up with the feeling that if I move too fast, if I say the wrong thing, something will notice.

So I’ll do what I’m told. I’ll keep flying. I’ll plan the trip. I’ll smile in photos. And when I stand on a beach with my feet in the surf, I won’t pray, and I won’t look too long at the horizon. Because I’ve learned this much, if nothing else: the sea doesn’t rage forever, and it doesn’t forget.