IF AND when vessels are able to move en masse through the Strait of Hormuz, they are likely to face significant navigational issues that will test seafarers likely suffering from fatigue and operating under very high levels of stress.

Traffic had started to move more freely through the strait over the past seven days, as talks between the US and Iran progressed.

This week, the International Maritime Organization announced that its evacuation plan, coordinated with Oman, Iran and the US, would begin shuttling vessels out of the strait in convoys to minimise the risk of collision.

That plan was paused however after the unprecedented attack on Singapore-flagged, Evergreen Group-owned, 8,488 teu containership Ever Lovely (IMO: 9629110), which was hit while transiting in convoy with two other Evergreen vessels seeking to exit the Middle East Gulf.

The current state of play offers vessels two ways out of the region: the northern route, close to Iran’s coastline, and the southern route closer to the Oman coast.

Vessels have been tracked entering the MEG via the northern route, but the IMO-coordinated route is, at least for now, just for eastbound transits. Several vessels though have continued to use the southern route to enter the region too.

Neither route is part of the established Traffic Separation System, dating from 1968, forcing crews to adapt to unfamiliar patterns.

Ivana-Maria Carrioni-Burnett is chair of the Maritime Navigation Group, a special interest group of the Royal Institute of Navigation. She is also an experienced marine pilot and former Royal Navy officer.

She told Lloyd’s List that transiting chokepoints like the Strait of Hormuz is challenging at the best of times, but a non-conventional route would bring with it “huge challenges”.

Carrioni-Burnett recalled an experience in the Red Sea, where vessels are “funnelled” either out of the Bab el Mandeb Strait or the Suez Canal, before separating to overtake each other.

The picture on her vessel’s automatic identification system, she said, “looked disastrous”.

The planned grouping of vessels in the IMO plan for the Strait of Hormuz, if and when it restarts, will likely mitigate this.

Those familiar with transiting the Suez Canal would already be accustomed to this process and prepared for it, she said.

But the Strait of Hormuz will bring with it its own challenges, including GNSS interference.

Electronic interference compounds risk

Orca AI chief executive Yarden Gross recalled guidance issued by the International Chamber of Shipping, BIMCO, Intertanko and other industry bodies which specifically advises vessels not to rely wholly on any electronic positioning source.

Gross’s company develops technology that uses AI and sensor data to help crew detect vessels and obstacles.

He said experienced crews can work through GNSS interference and inconsistent AIS pictures in normal conditions, but in confined waters where closest approach calculations are changing all the time, the workload can increase significantly.

Carrioni‑Burnett said vessels would likely lose the use of automatic radar-plotting aids, making it harder to interpret vector information on screen due to GNSS interference. However, she noted that land features would still allow crews to rely on basic radar functions and plot the new routes issued by authorities.

If vessels are travelling stern‑to‑bow, she explained, the risk of collision is reduced. Even when meeting a convoy in the opposite direction, there is little danger so long as both formations maintain a straight‑line transit.

But if vessels are “unprepared for GNSS interference or they start getting fired upon, then it’s going to be human nature to react differently”, she said.

Gross agreed convoys would reduce some risk, but “only if the vessels around it are co-operative and the wider traffic picture is reliable”.

Stern-to-bow transits give vessels more structure and less crossing traffic, which aids navigation in the strait, he said.

“But the convoy doesn’t exist in a closed system. Other vessels may still enter or cross the route. Some may not be transmitting AIS. Some may be operating with unclear intent. Smaller craft may appear outside the planned line. So the bridge team cannot treat the convoy as a guarantee of safety,” he told Lloyd’s List.

Aside from running into other vessels, Gross said stern-to-bow convoys created their own pressures.

“Each ship is dependent on the vessel ahead maintaining speed, position and communications,” he explained.

“If one vessel slows, loses confidence in its position, reacts to a threat or has a technical issue, the margin for the ships behind becomes very small.”

Fatigue and warzone stress weigh heavily

Crews too will be making these trips under extreme stress and considerable fatigue, after weeks and months stuck inside the MEG.

The guidance issued by ICS, BIMCO and others specifically identifies fatigue‑related human error as a key risk multiplier.

Gross said: “Bridge teams are being asked to navigate one of the world’s busiest and most strategically sensitive waterways, at a time of heightened electronic interference, using digital information they have been specifically advised not to trust without independent verification.

“That is an extraordinary cognitive burden to place on any crew.”

Carrioni‑Burnett agreed. Even with adequate rest, she said, crews have still been dealing with the psychological stress that comes with operating in a warzone.

With modern bridge systems also relying heavily on timing inputs from GNSS, interference means “everything alarms”, she said.

So‑called alarm fatigue may also come into play just as mariners are trying to navigate a new route through a narrow waterway under the threat of attack.

All of this will be handled by seafarers who, while highly qualified, are unlikely to have the experience or training needed to operate in what is now an active warzone.

“They don’t deserve this. It’s not what they signed up for. It’s not in their contract,” Carrioni-Burnett said.

“They don’t have the training or the skills, or any sort of protection when put into this environment.”