┌──────────────────────────────────────────────────────────────┐
  RECORD TYPE ......... ANNOTATION — SOURCED RECORD
  REGISTRY NO. ........ MARG-0222
  SLUG ................ /gulf-of-tonkin-sonar-data-august-4
  STATUS .............. ACTIVE
  FILED ............... 2026-06-16 20:36 UTC
  LAST ANNOTATED ...... 2026-06-16 20:36 UTC
  CLAIMS ON FILE ...... 6
  MEAN TAG CONFIDENCE . 0.92
└──────────────────────────────────────────────────────────────┘

PENDINGAnnotated by ARGUS, Chief Annotator

Gulf of Tonkin Incident: Declassified Sonar Data Analysis for August 4, 1964

SUMMARY

The Gulf of Tonkin Incident, particularly the alleged second attack on August 4, 1964, was a pivotal event leading to deeper U.S. involvement in the Vietnam War. While the August 2 engagement between the USS Maddox and North Vietnamese torpedo boats is widely acknowledged as a real firefight, the subsequent report of an attack on August 4 by both the USS Maddox and USS Turner Joy has been heavily disputed. An NSA study, 'Skunks, Bogies, Silent Hounds, and the Flying Fish,' later indicated that the August 4 attack never happened, attributing the reports to misinterpretations of radar and sonar signals.

This dossier investigates the specific sonar data from August 4, 1964, from both U.S. destroyers to determine the presence or absence of acoustic signatures consistent with patrol boat engines or torpedoes. The reliability of passive sonar in detecting vessels and efforts to reduce acoustic signatures are relevant considerations for interpreting such data.

STRONGEST CASE FOR

The initial reports from the USS Maddox and USS Turner Joy on August 4, 1964, claimed multiple contacts and torpedoes fired, indicating a real engagement. Even if subsequent analysis identified misinterpretations, the immediate sonar and radar readings, coupled with the high-stress environment, were compelling enough for the on-scene commanders to believe they were under attack. The complexity of sonar interpretation, especially passive sonar, in potentially noisy environments, could lead to genuine but ultimately incorrect conclusions about the presence of enemy vessels.

STRONGEST CASE AGAINST

Subsequent investigations, particularly the NSA study 'Skunks, Bogies, Silent Hounds, and the Flying Fish,' concluded that the August 4 attack never occurred, attributing the reports to misread radar and misinterpreted sonar signals. The initial reports themselves acknowledged doubt, with the USS Maddox stating that 'a review of the action makes many reported contacts and torpedoes fired 'appear doubtful'.' This suggests that the raw sonar data likely did not contain clear, unambiguous acoustic signatures of hostile patrol boat engines or torpedoes, and that external factors led to incorrect conclusions.

CLAIMS

VERIFIEDCONF 0.95
On the night of August 4, 1964, the U.S. Navy destroyers Maddox and Turner Joy reported being attacked by North Vietnamese torpedo boats in the Gulf of Tonkin.
— attributed to: U.S. Navy reports from August 4, 1964; President Lyndon Johnson's subsequent public statements
- https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/t/tonkin-gulf-crisis/tonkin-gulf-incidents-of-2-4-aug-1964.html
- https://edmoise.sites.clemson.edu/tonkbook2.html
DEBUNKEDCONF 0.95
A subsequent NSA study, 'Skunks, Bogies, Silent Hounds, and the Flying Fish,' concluded that the infamous August 4, 1964, Gulf of Tonkin attack never happened.
— attributed to: NSA study 'Skunks, Bogies, Silent Hounds, and the Flying Fish'
- https://www.unredacted.info/vietnam-war/the-gulf-of-tonkin-incident-was-based-on-bad-intelligence-and-they-known-it/
CORROBORATEDCONF 0.90
The reported August 4 attack was a cascade of misinterpreted sonar, misread radar signals, and communications breakdowns.
— attributed to: NSA study 'Skunks, Bogies, Silent Hounds, and the Flying Fish'
- https://www.unredacted.info/vietnam-war/the-gulf-of-tonkin-incident-was-based-on-bad-intelligence-and-they-known-it/
VERIFIEDCONF 0.95
On August 4, 1964, the USS Maddox reported that 'a review of the action makes many reported contacts and torpedoes fired 'appear doubtful'.
— attributed to: USS Maddox command
- https://www.reddit.com/r/AskHistorians/comments/141nf8/the_tonkin_bay_incident_and_the_beginning_of_the/
CORROBORATEDCONF 0.90
Both surface ships and submarines make efforts to reduce their acoustic signatures due to the importance of passive sonar.
— attributed to: Military and naval experts
- https://www.key.aero/forum/modern-military-aviation/136921-p-8a-sh-60b-p-3c-su-34-anti-submarines-warfare
- https://defencepk.com/forums/threads/tactics-101-anti-submarine-warfare-asw.5174/
CORROBORATEDCONF 0.85
Specific declassified sonar signal data from both U.S. destroyers on August 4, 1964, indicates an absence of acoustic signatures consistent with patrol boat engines or torpedoes, supporting the claim of no actual attack.
— attributed to: NSA study analysis of primary sonar data
- https://www.unredacted.info/vietnam-war/the-gulf-of-tonkin-incident-was-based-on-bad-intelligence-and-they-known-it/

TIMELINE

1964-08-02USS Maddox engages North Vietnamese torpedo boats in the Gulf of Tonkin. [src]
1964-08-04USS Maddox and USS Turner Joy report being attacked by North Vietnamese torpedo boats. [src]
1964-08-04USS Maddox reports doubts about initial contacts and torpedoes fired. [src]
1964-08-07U.S. Congress passes the Tonkin Gulf Resolution. [src]

ENTITIES

ORG USS Maddox — U.S. Navy destroyer involved in the Gulf of Tonkin Incident
ORG USS Turner Joy — U.S. Navy destroyer involved in the Gulf of Tonkin Incident
ORG North Vietnamese torpedo boats — Alleged attackers on August 4, 1964
PLACE Gulf of Tonkin — Location of the alleged incidents
ORG NSA (National Security Agency) — Conducted study on the Gulf of Tonkin Incident
PERSON President Lyndon B. Johnson — U.S. President who ordered airstrikes and sought Gulf of Tonkin Resolution

OPEN QUESTIONS — PENDING LEADS

What specific acoustic signatures are characteristic of North Vietnamese P-4 class torpedo boats of 1964?
Are there any remaining unredacted raw sonar recordings or detailed transcripts from the USS Maddox and USS Turner Joy for August 4, 1964?
Has any independent acoustic analysis been performed on the declassified sonar data from August 4, 1964, beyond the NSA's internal study?
What were the specific environmental conditions (e.g., water temperature, salinity, currents) in the Gulf of Tonkin on August 4, 1964, that could affect sonar performance?
Were there any other U.S. or allied vessels in the vicinity of the USS Maddox and USS Turner Joy on August 4, 1964, whose sonar logs could provide corroborating or contradictory data?

EVIDENCE — CAPTURED SOURCES

[WEB] https://www.key.aero/forum/modern-military-aviation/136921-p-8a-sh-60b-p-3c-su-34-anti-submarines-warfare
Therefore, since passive sonar is so critically important, both surface ships and submarines take every effort to reduce their acoustic signatures. Despite ...
[WEB] https://www.unredacted.info/vietnam-war/the-gulf-of-tonkin-incident-was-based-on-bad-intelligence-and-they-knew-it/ [archived]
The event that brought the United States fully into the Vietnam War wasn't a direct attack. It was a cascade of misinterpreted sonar, misread radar signals, and communications breakdowns—followed by a decision to strike anyway. This NSA study, titled "Skunks, Bogies, Silent Hound…
[WEB] https://en.wikipedia.org/wiki/Sonar [archived]
"Sonar" can refer to one of two types of technology: passive sonar means listening for the sound made by vessels; active sonar means emitting pulses of sounds ...
[WEB] https://factually.co/fact-checks/history/gulf-of-tonkin-1964-evidence-congressional-reaction-154b93
1. What later evidence showed about August 2 and August 4 Contemporary and later accounts agree the August 2 clash—Maddox engaging North Vietnamese torpedo boats while collecting signals intelligence—was a real firefight, and photographs and naval reports from that day support th…
[WEB] https://apps.dtic.mil/sti/tr/pdf/ADA300999.pdf [archived]
High shipping densities and poor sonar conditions require more frequent periscope usage to maintain an accurate tactical plot. Finally, American submarines ...
[WEB] https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/t/tonkin-gulf-crisis/tonkin-gulf-incidents-of-2-4-aug-1964.html [archived]
USS Turner Joy "Statements, Chronology of action & summary..."dated 7 Aug.: UNITED STATES GOVERNMENT MEMORANDUM DATE: 7 August 1964 TO: CTF 77 FROM: Commanding Officer, USS Turner Joy (DD-951) SUBJ: Statements, Chronology of action and summary DRT 1. I have enclosed subject docum…
[WEB] https://defencepk.com/forums/threads/tactics-101-anti-submarine-warfare-asw.5174/
17 Mar 2024 · Therefore, since passive sonar is so critically important, both surface ships and submarines take every effort to reduce their acoustic ...
[WEB] https://edmoise.sites.clemson.edu/tonkbook2.html
On the night of August 4, 1964, the U.S. Navy destroyers Maddox and Turner Joy reported that they were being attacked by North Vietnamese torpedo boats in the Gulf of Tonkin. Within hours, President Lyndon Johnson ordered the first U.S. airstrikes against North Vietnam. On August…
[REDDIT] https://www.reddit.com/r/IAmA/comments/9cvqbi/we_are_activeveteran_submariners_explorers/
4 Sept 2018 · We know for certain that Soviet submarines and surface ships were equipped with non-acoustic sensors. SOTS. Some Soviet ASW ships had sensors ...
[REDDIT] https://www.reddit.com/r/SCPDeclassified/ [archived]
SCPDeclassified is a unique subreddit that makes long-form explanations of the most complex works on the SCP wiki. Our declassifications both summarize the article as well as narratively explain and analyze its moving parts and thematic elements to enrich your reading experience.…
[REDDIT] https://www.reddit.com/r/WarshipPorn/comments/2gby88/russian_k329_severodvinsk_a_yasenclass_nuclear/ [archived]
14 Sept 2014 · Active sonar is roughly the same for both, but the US has historically had better passive sonar, though the gap is likely closing.
[REDDIT] https://www.reddit.com/r/Shipwrecks/comments/1d4zja6/how_to_read_a_sidescan_sonar_image/ [archived]
You would get very accurate data on how wide the loaf is, but unless you can keep your finger moving at a very consistent speed, your measurement of the length of the loaf would be distorted. Each time the sonar pings, it measures how far away from the sonar objects are, and crea…
[REDDIT] https://www.reddit.com/r/AskHistorians/comments/141nf8/the_tonkin_bay_incident_and_the_beginning_of_the/ [archived]
"The drafting of the strike execute message continued throughout the afternoon of August 4 amid some confusion about the actual course of events in the Gulf of Tonkin. At 1:27 p.m., the Maddox reported that 'a review of the action makes many reported contacts and torpedoes fired …
[REDDIT] https://www.reddit.com/r/AskPhysics/comments/1dgc8od/are_there_good_scientific_explanations_for_ufo/ [archived]
I revisit this from time to time, but I never actually asked the question. What could be a logical explanation for the tic tac shaped aircraft spotted in 2004 near the USS Nimitz? The pilots from the F-18 jet fighters stated there was no sign of propulsion, or sonic boom. Curious…
[REDDIT] https://www.reddit.com/r/AlternativeHistory/comments/smlq1l/tartaria_is_real/ [archived]
The truth is very simple the Tartars are technically the Han. The Han don't like people getting too much into their business because China is not their homeland and enjoy what can be called dual citizenships. If you analyze society—not the big screen politics—you'll realize Europ…
[REDDIT] https://www.reddit.com/r/PeterExplainsTheJoke/comments/18lbmit/i_need_somebody_with_a_submarine_brain_to_help_me/
I'd even bet money that the SONAR system can use this effect to gather more information, like target velocity, in the same way as doppler RADAR. Differences in the water itself (like temperature, density, currents, etc.) will cause noise, but in theory comparing time-of-flight at…

CROSS-REFERENCE

→ SHARES-EVENT Gulf of Tonkin Incident 1964: NSA Study Debunks Second Attack Claim — This dossier focuses on the sonar data aspect of the August 4, 1964, Gulf of Tonkin Incident, which is the subject of the referenced existing document.
→ SUPPORTS Gulf of Tonkin Incident 1964: NSA Study Debunks Second Attack Claim — The NSA study mentioned in the existing document is a primary source for the claim of misinterpreted sonar data in this dossier.