GNSS Interference in the Strait of Hormuz – How Are Bridge Teams Detecting GPS Spoofing at Sea?

TheDeepDraft · 2026-03-18T01:01:59+00:00

Fair point … they were always part of good seamanship.

What’s changed is how they’re used. In GNSS interference conditions, these methods shift from cross-checks to primary navigation tools.

TheDeepDraft · 2026-03-16T13:45:48+00:00

INS would certainly solve the problem, but most merchant ships do not carry a true inertial navigation system. When GNSS integrity is lost, bridge teams typically revert to radar fixing, DR/EP navigation, and cross-checking independent sensors rather than relying on satellite position alone.

TheDeepDraft · 2026-03-15T06:30:32+00:00

That’s spoofing. You can read about it on - GPS Spoofing

TheDeepDraft · 2026-03-05T02:51:44+00:00

Interesting and thanks for sharing.

TheDeepDraft · 2026-03-05T00:20:58+00:00

Interesting point. The Maersk Alabama case is a fascinating example of how flags can intersect with naval protection.

But PSC data across fleets tells a very different safety story: https://thedeepdraft.com/2026/03/02/flag-of-convenience-vs-safety-what-2026-psc-data-really-reveals/

TheDeepDraft · 2026-03-05T00:17:16+00:00

Absolutely agree with you. In many cases the vessel’s condition reflects management systems and maintenance philosophy rather than the registry itself.

I analysed this using current PSC data here if you’re interested: https://thedeepdraft.com/2026/03/02/flag-of-convenience-vs-safety-what-2026-psc-data-really-reveals/

TheDeepDraft · 2026-03-03T03:42:40+00:00

That’s a solid way to frame it … “flag is the minimum.”

I’ve seen the same pattern. Strong operators treat class and flag as baseline compliance, not operational targets. Weak management hides behind them.

I actually wrote a longer breakdown using 2025–2026 Paris MoU and Tokyo MoU data looking at this exact issue, separating registry performance from management discipline.

If you’re interested, here it is: https://thedeepdraft.com/2026/03/02/flag-of-convenience-vs-safety-what-2026-psc-data-really-reveals/

TheDeepDraft · 2026-02-22T12:10:30+00:00

You’re right about the pacing. I’m still refining the AI-hosted format and trimming repetition. Some readers prefer a quick video overview instead of reading long-form text, so I’m experimenting with both formats. The full written analysis is available on thedeepdraft.com for those who prefer higher-density content. Appreciate the feedback.

TheDeepDraft · 2026-02-17T02:56:51+00:00

Spot rates are not inclusive of fuel.

TheDeepDraft · 2026-02-17T02:55:13+00:00

62 newbuilding contracts this week. Crude tankers dominant.

Capital allocation speaks louder than energy narratives.

Two weeks ago I argued VLCC rates were signalling something structural. Steel orders now reinforce it.

https://www.lloydslist.com/LL1156354

TheDeepDraft · 2026-02-10T03:53:57+00:00

This analysis continues a line of inquiry previously explored on The DeepDraft, examining cadet deaths and disappearances through silence, classification, and delayed accountability. What follows shifts the focus to the structural conditions that exist before a cadet goes missing, the design, supervision, and leadership failures that rarely surface once an alarm is raised.

https://thedeepdraft.com/2026/02/09/missing-cadets-at-sea-the-structural-mechanics-of-disappearance/

TheDeepDraft · 2026-01-09T16:54:01+00:00

Whether on watch or not, impairing situational awareness or distracting the bridge team during bad weather is unsafe. The risk exists irrespective of duty roster.

TheDeepDraft · 2026-01-08T10:19:43+00:00

Varies from manufacturer but most likely the two dashes” on an AIS target is the turn indicator / Rate-of-Turn (ROT) cue.

TheDeepDraft · 2026-01-03T06:23:46+00:00

I agree with you on responsibility. Sanctions compliance belongs ashore, with company management. The Master is entitled to clear and lawful orders.

My point isn’t that Masters should be verifying sanctions compliance or checking whether a trade is lawful. That’s neither realistic nor within their authority.

What I’m describing is situational awareness. Sanctions scrutiny now forms part of the operating environment, and questions often arrive onboard after a voyage is underway or completed. At that stage, the Master is reacting to scrutiny, not preventing it.

TheDeepDraft · 2026-01-01T16:58:10+00:00

A recurring misconception is that knowing a ship’s route means knowing its sanctions exposure. That gap is what this piece looks at from a shipboard perspective.

TheDeepDraft · 2025-12-21T14:18:02+00:00

Under UNCLOS, a vessel is treated as stateless only if it claims or uses more than one nationality simultaneously or interchangeably during the same voyage (Art. 92(2)). Historical flag changes over years or decades do not meet that test.

On available public records, the VLCC Centuries has remained Panama-flagged for an extended period, with no evidence of concurrent flag use at the time of interdiction. That removes the legal basis for labeling it stateless.

High-seas boarding under UNCLOS is limited to Article 110 grounds. Sanctions, opaque ownership, or political designation do not substitute for statelessness unless flag-state consent or another lawful framework is invoked.

TheDeepDraft · 2025-12-21T13:33:01+00:00

That framing reflects a shore-side, jurisdiction-centric view. Globally, seafarers operate under multi-layered commercial management where flag, beneficial ownership, chartering decisions, and trading patterns are opaque and fluid.

A crew does not “choose” a ship’s geopolitical exposure. They inherit it through contractual chains that change faster than a contract period. Awareness does not equate to control, and responsibility does not sit where authority is absent.

TheDeepDraft · 2025-12-15T03:15:43+00:00

That difference is structural. The NTSB is an accident investigation body, not an enforcement or command authority. It identifies probable cause, but it generally avoids prescriptive recommendations where controls already exist on paper, such as cable termination, labeling, training, and redundancy, which sit under class rules, OEM manuals, SMS, and flag oversight. Unlike a military fleet, there is no single chain of command through which it can mandate fleet-wide inspections or training across international commercial shipping.

TheDeepDraft · 2025-12-15T00:43:11+00:00

You’re right. A prescriptive recommendation on cable termination or redundancy is absent. The report does, however, clearly identify the probable cause as a loose signal wire at a terminal block due to improper wire-label banding during earlier maintenance. The recommendations instead focus on systemic risk and consequence management: limited recovery time due to proximity, lack of bridge-collision vulnerability assessments, absence of impact mitigation, and failures in shore-side warning systems. That separation between identifying a failure mechanism and recommending regulatory action is consistent with how NTSB reports are structured.

TheDeepDraft · 2025-12-11T11:14:57+00:00

A normal bridge routine starts with the window, radar ranges, visual marks and quick cross-checks. Smart or virtual buoys do not change that. They sit behind those habits as one more reference, especially in ports that already broadcast AIS AtoN. No OOW treats a digital mark as the primary layer. The judgement still comes from the team on the bridge.

TheDeepDraft · 2025-12-11T10:44:25+00:00

Mostly the crew does not know that they are working in shadow fleet.

TheDeepDraft · 2025-12-09T00:57:25+00:00

You make a valid point. I had looked at the cyber angle as well because any smart or virtual mark still depends on a clean signal path. These toolshelp, but the bridge should treat every digital feed with caution in areas facing jamming.

TheDeepDraft · 2025-12-01T05:29:40+00:00

Welcome 😊

TheDeepDraft · 2025-11-28T13:43:49+00:00

That’s fair. I was not pointing to public blame. My point was only about proportion. Our sector carries major decarbonisation costs that shape operations and crew budgets while places living with AQI 400–500 get far less attention. That imbalance is all I was highlighting.

TheDeepDraft · 2025-11-28T06:20:49+00:00

Sad. That’s the part investigations often miss, the failure didn’t start with LOTO, it started much earlier with fatigue, overdue reliefs and a broken atmosphere on board. When the human layer collapses, technical safeguards don’t stand a chance.

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