A comprehensive guide to marine sextant – principles, usage, and maintenance

The sextant is a valuable instrument used to determine the angle between the horizon and a celestial body like the Sun, Moon or Star. It is used in celestial navigation to find out the latitude and longitude.

From MarineInsight by  Shilavadra Bhattacharjee

 

Sextant derives its name from the Latin word’ sextus; or ‘one-sixth’, as the sextant’s arc spans 60° or one-sixth of a circle.

Octans with 45° arcs were initially used to determine the latitude.

However, Sextants were developed with wider arcs to calculate longitude from lunar observations.

They replaced octants by the latter half of the 18th century.

It consists of an arc of a circle marked in degrees. It also has a movable radial arm pivoted at the circle’s centre.

There is a telescope mounted to the framework, which is lined with the horizon.

A mirror is placed on the radial arm.

It is moved or adjusted until the celestial body is reflected into a half-silvered mirror in line with the telescope and appears to coincide with the horizon through the telescope.

The angular distance of the celestial body or star above the horizon is read from the graduated arc of the sextant.

Mainly used at sea, the tool is so named because its arc is one-sixth of a circle – 60 degrees.

It adheres to the principle of double reflection hence it can measure angles up to 120 degrees. Practically speaking, the arc of the sextant is a little over 60 degrees, and therefore the total angle measurable is about 130 degrees.

Sextant is an essential tool for celestial navigation and is also used by mariners to measure the angle between the horizon and a visible object (or two objects at sea).

Hold the sextant vertically and point it in the direction of the celestial body.

See the horizon through an unsilvered part of the horizon mirror.

Continue to move or adjust the index arm until the image of the star/sun, which has been reflected by the index mirror and then by the silvered portion of the horizon mirror, seems to rest on the horizon.

The altitude of the celestial body can be determined by reading from the scale on the arc of the sextant’s frame.

The sextant is used to measure the following:

• Vertical Sextant Angle (VSA)
• Horizontal Sextant Angle (HSA)
• Altitudes

Brief History Of Sextant

A ship’s altitude above the horizon was related directly to the ship’s latitude. Mariners began to invent tools for measuring these factors to aid in navigation.

One of the simplest was the kamal used by Arab navigators from the 6th century onwards.

A 2-inch long rectangle board was used.

A string with evenly spaced knots was attached to it. This arrangement was called a kamal.

The navigator held the string using his teeth and moved this board farther from his body, aligning its bottom edge with the horizon and the top with the object, generally the Polaris or the north star.

The number of knots between the mouth and the board gave an idea of the relative height.

Although kamal was quite useful, it was not precise enough and, by the 13th century, gave way to the astrolabe and the mariner’s Quadrant.

The Quadrant was popular with Portuguese explorers that travelled south along the African coast to search for a route to the Orient.

When the seafarers reached close to the equator heading south, Polaris disappeared below the horizon. Hence, in the southern seas, mariners used another way to find their latitude.

Per instructions from Prince Henry of Portugal, by 1480, Portuguese astronomers had found a way to determine the latitude using the position of the Sun when it moved north and south of the equator with changing seasons, what we now refer to as its declination.

To put it simply, the navigator could calculate the Altura or altitude and latitude by using his Quadrant to take the altitude of the Sun when it came to its highest altitude at local noon and then make a correction for the position of the sun north or south of the equator per the date.

Columbus used it extensively on his voyages to the New World.

He marked off the latitudes of places he visited, such as Lisbon, Serra Leoa, Cabo Verde and other places he might have landed.

Also, it was common for navigators during those times to record the altitude of the Polaris in degrees at ports where they wished to return again.

Hence, lists of alturas of many ports were published to guide the seafarers up and down the coasts of Africa and Europe.

Principle of the Sextant

 

When a ray of light is reflected by a plane mirror, the angle of the incident ray is equal to the angle of the reflected ray; when the incident ray, reflected ray and the normal lie on the same plane
When a ray of light suffers two successive reflections in the same plane by two plane mirrors, the angle between the incident ray and the reflected ray is twice the angle between the mirrors
 

Different Parts Of A Sextant

A sextant is shaped in the form of a sector (60 degrees or 1/6th of a circle).

It is the reason the navigational instrument is called a Sextant (the Latin word for 1/6th is Sextans).

The sector-shaped part is called the frame.

A horizontal mirror is attached to the frame, along with the index mirror, shade glasses (sunshades), telescope, graduated scale and a micrometre drum gauge.

How Does A Sextant Work And How To Use It?

Watch this video to understand how to use a sextant.

Navigation Sextant – Readings ON and OFF the arc

The normal graduations of the arc, to the left of zero, extending from 0 to 130 degrees, are referred to as ON the arc.

To the right of 0 degrees, the graduations extend for a few degrees and are referred to as OFF the arc. When reading OFF the arc, graduations of the micrometer should be read in the reverse direction (59 as 1′, 55 as 1′ and so on).

Errors of the Sextant

The errors can be classified as

1. Adjustable Errors (adjustable onboard), and 
2. Non-adjustable Errors (not adjustable onboard)

Adjustable Sextant Errors

• The Perpendicularity error : This is caused when the index glass is not perpendicular to the plane of the instrument. To check for this, clamp the index bar about the middle of the arc, and holding the sextant horizontally, with the arc away from you, look obliquely into the index mirror till the arc of the sextant and its reflection on the index mirror is simultaneous. If in alignment, the error does not exist. If not, turn the adjustment screw at the back of the index glass until they are aligned. 

• Side Error: This is caused by the horizon glass not being perpendicular to the plane of the instrument. Clamp the index bar at 0 degrees 0.0′. Hold the sextant vertically and look at the heavenly body. Turn the micrometre one way and then the other while looking at the body. The reflected image of the body will move above and below the direct image and should pass exactly over it. If the reflected image passes to the left or right of the direct image, a side error exists. This error can be removed by turning the second adjustment screw (the top screw behind the horizon glass) until the true and reflected horizons appear in the same line.

• Index Error: This is caused if the index mirror and the horizon glass are not exactly parallel to each other when the index is set at 0 degrees 0.0′. Basically, this is the difference between the optical zero of the sextant and its graduated zero, termed OFF the arc if the optical zero lies to the right of the graduated zero and termed ON the arc if the optical zero lies to the left of the graduated zero. There are three methods of obtaining the index error of a sextant:

A) By observing the horizon: 

Clamp the index at 0 deg 0.0′ and, holding the sextant vertical, look at the horizon.

The reflected image and the direct image should appear in a perfect line.

If not, turn the micrometer until they coincide exactly.

The reading of the micrometre, ON or OFF the arc, gives the IE

B) By observing the star or planet: Clamp the index at 0 deg 0.0′ and holding the sextant vertical, look at the star/planet. The reflected and direct image must coincide. If not, turn the micrometer till they do. The reading of the micrometre, ON or OFF the arc, gives the IE

C) By observing the Sun:

Set the index at about 32′ ON the arc. Hold the sextant vertically and look at the Sun, using shades.

The reflected image of the Sun would appear below the direct image.

Turn the micrometer until their closer limbs just touch.

Note reading ON the arc.
Set the index at about 32′ OFF the arc and look at the Sun.

The reflected image of the Sun would appear above the direct image.

Turn the micrometer until their closer limbs just touch.

Note reading OFF the arc.
The name of IE is the name of the reading having a higher numerical value.

The error of Collimation: 

This is due to the axis of the telescope not being parallel to the plane of the instrument.

The telescope is attached to the sextant in such a manner that it cannot tilt.

These modern sextants are, therefore, not provided with any collimating screws

Non-Adjustable Errors Of Sextant

 

• Graduation Error: Due to the inaccurate graduation of the main scale on the arc or of the micrometre/vernier
• Centring Error: Caused if the pivot of the index bar is not situated at the geometric centre of the arc. This can be caused due to a manufacturing defect or due to careless handling.
• Shade Error: The shades should be so mounted that their glass surfaces are normal to the rays of light passing through them. If not, the distortion would result. The greater number of shades used, the greater the chances of distortion.
• Optical Errors: Caused by prismatic errors of the mirrors or aberrations in the telescope lens
• Wear on the rack and worm: This causes a backlash, leading to inconsistent errors. Wearing down of the worm can be due to lack of lubrication, the presence of dust particles, careless handling.

Dip

This is the angle at the observer between the plane of the observer’s sensible horizon and the direction of his visible horizon.

A dip occurs because the observer is not at sea level.

The value of the dip increases as the height of the eye of the observer increases.

The values of dip are given on the cover page of the nautical almanac and in nautical tables (Nories) as a function of the height of the eye.

Pointers on the use of a sextant

1. Always check the errors before use
2. Focus the telescope while looking at the horizon and make a mark on the circumference of the stem
3. During use, hold the sextant steady. For this, stand with feet slightly apart for balance with hands holding the sextant steady
4. While observing the altitude of a celestial body, remember to swing the sextant to the other side; the body will appear to move along the arc. Measure the altitude at the lowest point on this arc
5. Stand as close as practicable to the centerline of the ship
6. Use appropriate dark shades while observing the Sun
7. If a backlash error exists, remember to rotate the micrometer in one direction only
8. Altitudes of stars and planets should be taken during twilight
9. Nighttime sextant observations should be avoided as far as practicable. The strong moonlight gives the illusion of a good horizon which is most probably false
10. While observing the HSA, set the index at zero, look at the object on the right through the telescope, gradually swing the index around and finish while facing the object on the left
11. When measuring VSA, look at the top of the object, set the index at zero and look at the top of the object. VSA = height of the object in meters          1852 X Tan VSA

Care and maintenance of a sextant

1. Do not put too much stress on the index bar when grasping a sextant
2. Never touch the arc. It will smear it. These aren’t oleophobic per se
3. Ensure that the worm and rack are clean
4. Coat worm and rack with Vaseline when not using it for too long
5. Mirrors, lenses and shades should be wiped clean with a soft cloth
6. After each use, gently wipe the index mirror, horizon glass
7. Put it in the box when not using it
8. Do not bump the sextant anywhere
9. Avoid exposure to sunlight
10. Keep sextant stowed away from direct sunlight, dampness, heaters or blowers

The sextant is an expensive, precision instrument which should be handled with utmost care.

Reference: Principles of Navigation by Capt. Joseph & Capt. Rewari, The Marine Sextant by Capt. H. Subramaniam

From Yanbu to Sohar: Tracking Saudi Arabia’s alternative oil routes

 

(Al Jazeera)

From AlJazeera by Hanna Duggal

The world’s second-largest crude exporter is rerouting crude via dark shipments and ship-to-ship transfers off Oman.

Saudi Arabia’s oil exports took another blow last week when drone attacks knocked out part of the country’s East-West pipeline, halting oil flow and removing 4-5 million barrels per day (bpd) of oil from global supply.

It is unclear how long repairs will take, although The Associated Press estimates three to five weeks, citing two regional officials.

The 1,200km (746-mile) pipeline connects the kingdom’s main oil-producing fields in the east of the country with Yanbu port on the Red Sea coast in the west, allowing Saudi crude to bypass the Strait of Hormuz, which has largely remained closed since the United States-Israel war on Iran began on February 28.

As the world’s second-largest oil producer, Saudi Arabia’s ability to keep crude flowing has significant consequences for global energy markets. Al Jazeera asked experts what alternatives remain, how the disruption could affect buyers worldwide, and what it means for the kingdom’s revenues.

 

 

(Al Jazeera)

Exports down more than 70 percent

Total Saudi crude loadings, which topped 7.5 million bpd in January and February, had fallen to about 2.3 million bpd in August and roughly 2.1 million bpd in the first half of September – a drop of more than 70 percent.

Analysts caution the real loadings figure may run somewhat higher, since shuttle tankers crossing Hormuz with tracking switched off aren’t always captured in vessel data.

How can Saudi Arabia export its oil?

Saudi exports are built around two coastal passages – the Gulf in the east, where crude moves out through the Strait of Hormuz, and the Red Sea in the west, where it can travel either north through the Suez Canal and Sumed Pipeline, or south through the Bab al-Mandeb strait.
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Route one: The Strait of Hormuz

Before the crisis, most Saudi crude left on ships through the Strait of Hormuz, the 39km (24-mile) shipping choke point connecting the Gulf to the Gulf of Oman, and the open sea beyond.

Saudi Arabia was exporting about 7-8 million bpd of oil, with most seaborne volumes loading at the terminals of Ras Tanura and Ras al-Ju’aymah, and the former averaging about 5.4 million bpd in 2025.

The route is the most direct and economical way to reach Asia, which buys the bulk of Saudi crude exports.

 

Dark ships and ship-to-ship transfers

With the western pipeline route closed and the Red Sea’s southern route hostile, Saudi Arabia has little choice but to push exports back through the Gulf – despite the restrictions, higher costs, and physical risk of attack that come with transiting Hormuz, experts say.
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“With the East-West pipeline offline, Saudi’s options are limited. The first is shipping more crude from its Gulf terminals through the Strait of Hormuz, including ship-to-ship transfers outside the strait, such as off Sohar in Oman,” according to Rishi Rajanala, research specialist in Oil Americas at LSEG Data & Analytics.

 

 

A satellite image of side-by-side ships at sea, off the coast of Sohar, Oman, on June 9, 2026

[Airbus DS/Handout via Reuters]

“Gulf producers have already been moving part of their exports this way, but volumes depend on tanker availability, insurance and freight costs, and remain well below pre-war levels.

“The second is drawing on crude already stored on the west coast and at Egypt’s Ain Sukhna and Sidi Kerir terminals, which can continue to supply Europe through the Sumed Pipeline, but only for as long as stored volumes last. The third is a phased restart of the pipeline itself, depending on the extent of the damage.”

Richard Matthews, director of consultancy and research at Gibson Shipbrokers, a London-based shipping services company, said transiting back through Hormuz will “further fuel higher freight costs for Middle East exports and create additional inefficiencies”, adding, “we do not know how long Yanbu loadings will be suspended for, but it doesn’t look to be a quick fix.”

One way to reduce that risk is for tankers to go “dark” by switching off their AIS transponders – used in maritime navigation to identify and track vessels – as they transit Omani coastal waters. 

“They will transit with transponders off and likely coordinate with the US Navy but still face the risk of attack as everyone else does,” Matthews said.

If the outage extends beyond a few weeks, the balance shifts further: Stored volumes would run down, and any crude that cannot move through the Gulf would have to be stored or left unproduced, adding pressure to production levels already well below pre-war volumes in August.

Rahul Choudhary, vice president of Upstream Research at Rystad Energy, an independent energy research company, said Hormuz-route exports increased in September to more than two million bpd in the first two weeks, roughly one million bpd above August.

“We expect Strait of Hormuz exports to rise further in the second half of the month, already evident in Aramco offering additional loadings to Asian refiners out of Sohar. Saudi Arabia can lean further on dark tanker activity in the coming days to offset Yanbu losses,” he added.

Route two: The East-West pipeline to Yanbu

Most of Saudi Arabia’s crude is produced in the east, and Aramco’s East-West pipeline links the Ghawar and Abqaiq processing facilities there to Yanbu port on the opposite side of the country.

It was built in 1981, during the Iran-Iraq war, precisely to reduce reliance on the Strait of Hormuz in a crisis of the kind Saudi Arabia and other Gulf exporters are now facing.

It runs at a maximum capacity of about 7 million bpd.

Crude shipped from Yanbu has two ways to travel onward through the Red Sea – south via Bab al-Mandeb or north via Suez.

South, via Bab al-Mandeb

Shipments heading south to Asia must pass through the Bab al-Mandeb strait – the second-best route after Hormuz.

But Iran-backed Houthi forces launched a rapid military offensive in September, seizing the Yemeni port of Mocha, the coastal town of Dhubab, and Mayyun Island, and now control the strait.

They have also declared a maritime embargo on Saudi Arabia, prohibiting vessels from loading or discharging cargo at Saudi ports.

 

(Al Jazeera)

North, via the Suez Canal

With the southern exit blocked, tankers wishing to reach Asia must instead travel north.

Oil tankers can pass through the Suez Canal directly, or discharge their cargo at Egypt’s Ain Sokhna terminal on the Red Sea into the Sumed pipeline, which carries it overland across Egypt to a Mediterranean port near Alexandria, where it is reloaded onto tankers bound for Europe.

Very Large Crude Carriers (VLCCs) are too large to transit the canal at full draft – the maximum safe depth when fully loaded – so they instead partially discharge at Ain Sokhna and reload the remaining volume at the Mediterranean terminal before continuing.

According to HSBC Global Investment Research, Aramco had planned a similar “shuttling” operation before Yanbu was suspended, using smaller Suezmax tankers to move crude between Yanbu and Ain Sokhna.

 

 

A composite satellite image shows a trail of smoke rising, as Yemen’s Iran-aligned Houthis said on July 25, 2026 that they carried out operations against Saudi Aramco facilities in Jizan and Yanbu [European Union/Copernicus Sentinel-2/Handout via Reuters]

From there, reaching Asian buyers means sailing west through the Strait of Gibraltar and around the Cape of Good Hope – a journey of about 13,140 nautical miles (equivalent to about 24,335km) that dwarfs the roughly 3,370 nautical miles (6,241km), 10-day journey via Hormuz, adding almost a month to the voyage and making shipping far more expensive while tying up tankers for longer.

But some experts expect the East-West pipeline to resume operations sooner, offering hope that Saudi oil exports could return to more sustainable levels.

Choudhary said: “We expect the pipeline to restart within a couple of weeks at a reduced 40-60 percent capacity, flowing around 2.5-3 million bpd. With Saudi likely to prioritise refinery runs, only about 0.5-1 million bpd would be left for export, meaning Yanbu crude exports fall by 2.5-3 million bpd even after a partial restart.

“Part of that gap can be covered by higher Hormuz liftings and increased dark-fleet activity, bringing the net impact on Saudi crude exports down to roughly 1.5-2 million bpd.”

Why trucking is not a viable option

One option conspicuously absent from Saudi planning is trucking – and the maths explains why. The kingdom typically exports 5-7 million bpd.

Replacing even a single day’s volume by road would require roughly 25,000 to 35,000 fully loaded tanker trucks, each carrying about 200 barrels.

Lined up bumper-to-bumper, that convoy would stretch nearly 500km (310 miles) – roughly the distance from Riyadh to the nearest coast.

A single VLCC, by comparison, carries about 2 million barrels in one voyage, and the pipeline itself moves millions of barrels daily with minimal manpower – which is why, even with its main export arteries compromised, Saudi Arabia’s fallback plan runs through ships, not roads.

The impact on global markets

Oil prices have so far been cushioned by stockpiles and releases from strategic reserves, with Brent crude trading at about $70-$90 a barrel in recent months.

But the longer regional disruptions continue, the more we may see prices rise, with Brent crude currently trading above $105 a barrel.

“The market is pricing a significant loss of supply, with the length of the outage as the main uncertainty. Saudi authorities have not given a timeline for the repair, and estimates reported so far range from a few days to eight weeks for a full recovery,” Rajanala, the research specialist at LSEG, said.

What does this mean for buyers of Saudi oil?

Saudi Arabia was, until recently, the world’s largest oil exporter.

Its main buyers are Asian and European refiners, including China, which bought 22 percent of Saudi Arabia’s oil, followed by South Korea (14 percent), Japan (13 percent), India (10 percent) and the US (5 percent).

Those buyers are already feeling the shutdown.

Cargoes scheduled for European refiners are being cancelled, forcing many companies to look elsewhere for their oil, including turning to the US, North Sea and West Africa.

“Some European refiners with cancelled Saudi cargoes are already sourcing crude from the North Sea and seeking cargoes from the Americas and Central Asia, while Asian buyers are being offered alternative loadings from the Gulf,” Rajanala said.

“The missing barrels are also higher sulphur crude. Saudi grades such as Arab Light and Arab Medium are difficult to replace, like-for-like, because the alternatives available from the US, Kazakhstan and much of the North Sea are generally lower in sulphur content. That puts particular pressure on refiners configured for Middle East crude, many of them in Asia, which takes the largest share of Saudi exports.”

What does this mean for Saudi Arabia’s revenues?

Despite higher oil prices benefitting Saudi Arabia, they are being offset by an inability to physically export at normal volumes.

The government depends heavily on dividends, royalties and taxes from Aramco, with its crude and petroleum products sales accounting for more than half of government revenues, generating 606.5 billion riyals ($162bn) for state coffers in 2025.

Sustained disruption would cut deep into public finances.

UBS Research now forecasts the 2026 budget deficit reaching 5 percent of gross domestic product against an original target of 3.3 percent.

Louis Vincent-Gave, from Gavekal Research, an independent research firm, noted that “the bombing of Yanbu, combined with the bombing of the East-West pipeline, and the Houthi takeover of the Bab el-Mandab sea passage, suddenly places large question marks on the ability of Saudi oil to keep flowing through the Red Sea to the rest of the world. And if Saudi Arabia cannot keep pumping oil to the rest of the world, the Saudi government could end up selling assets – US treasuries? Stakes in private equity funds? Artificial intelligence investments? – to pay its immediate bills.”

Is traffic through Hormuz really back to normal?

photograph: getty images

From The Economist

America would like the world to think so as oil prices top $100 again

Listen to donald trump and normality reigns in the world’s most contested waterway.
America and Iran may be firing again, but “Hormuz Oil Volumes are back,” declared the president on September 3rd.
He claims that 18m barrels a day (b/d) now pass through the strait—just shy of the pre-war average of 20m.
J.D. Vance, his vice-president, says Iran’s control of Hormuz is “effectively gone”.
“A big lie,” counters Mohsen Rezaei, Iran’s top security official.
He puts daily crossings at seven or eight ships, far below the 30-40 that Mr Trump’s camp claims.
Ship-trackers are sceptical, too: Kpler, a data firm, has traffic below 5m b/d in the week to August 30th.
Even the Joint Maritime Information Centre, linked to America’s navy, cannot square its count of nearly 30 daily passages with the single digits independent trackers typically report.

Neither side has much incentive to show its workings, points out Shahin Iraninejad of gssi, a sovereign-risk advisory firm.
America wants voters to believe the millions of dollars it splashes daily on escorting tankers in the Gulf are paying off; Iran wants to look in control of the strait, even as more oil slips through.
But reality matters.
The more Gulf exports are throttled, the deeper importers must dip into stocks or bid up oil elsewhere; Brent crude is back above $100 a barrel for the first time since July.
So who is closer to the truth?

 

chart: the economist

The truth is murky because most tankers now cross with transponders off, to avoid becoming targets.
Some broadcast signals, but pervasive radio jamming blurs the picture.
Others tamper with their own radios to fake their location.
Most transits also happen at night, out of satellites’ view.
Complicating matters, Gulf barrels often change hands before reaching the high seas: a handful of firms—Gulf state-owned shipowners, Sinokor of South Korea and Greek owners such as Dynacom—carry most of the traffic, shuttling oil through the strait before clandestinely transferring cargo outside it.

So tanker-counters infer transits retroactively, tracking loadings and discharges and watching for vessels that vanish from the Gulf only to resurface outside it, explains Pamela Munger of Vortexa, another ship-tracker.
Passages are often confirmed with a lag, so initial numbers are best read as a floor, revised up as more transits surface.
Kpler recently raised its estimate for the week to August 10th to 7.2m b/d, up from an initial calculation of 4.7m.

 

 

Assuming similar undercounting throughout August, Kpler’s eventual reading at the turn of the month may near the 9m b/d seven-day average that Chris Wright, America’s energy secretary, cited on September 6th.
Part of the gap lies in definitions: what counts as oil (crude only or products too); where the counting line sits (the strait or the Gulf of Oman); and when a barrel is dated (at loading, at crossing or on reappearance).
Commercial trackers like Kpler and Vortexa are clear about their methodology; officials are not, and probably favour generous definitions.

That still doesn’t explain Mr Trump’s 18m b/d.
Perhaps he cherry-picked an exceptional day: since March, counting every possible oil product, Vortexa has recorded only two days above 16m.
Or maybe he mixed in exports that now bypass the strait entirely.
Since February Saudi Arabia has pushed more crude through its East-West pipeline, lifting exports from its Red Sea ports by 1m-3m b/d; the United Arab Emirates has rerouted around 1m b/d through a pipeline to Fujairah.
Add a little more from Oman, over a favourable window, and bypass routes may amount to 5m b/d.

Either way, the figure is not helpful.
Shipping flows are bumpy, so weekly averages say more than daily tallies.
The latest tit-for-tat, plus Iranian threats against tankers shuttling crude through the strait, has curbed transits drastically in recent days, notes John Ollett of Argus Media, a price-reporting agency.
On September 8th Kpler counted just eight transits, down from 23 a week before.
Attacks by Yemen’s Houthi rebels on ships and Saudi targets have also slowed Red Sea shipments.

That points to a sober reality for Mr Trump: past Hormuz traffic does not predict future performance because progress can reverse quickly.
No amount of American spin has brought insurance rates for crossing Hormuz below 10%of a ship’s value (they averaged 0.25% before the war).
Even if mines have been cleared from parts of the strait, as Mr Trump claims, they can drift in from elsewhere, and Iran can lay new ones.
Its forces also retain ample capacity to strike tankers.

Oil markets are already showing signs of stress.
North Sea Dated, a near-term crude benchmark, is approaching $110 a barrel, up from $70 in June.
Diesel has burst through $190 a barrel in America and Europe, nearly double its price in February.
Mr Trump can fight a data war all he likes.
What matters is how many importers receive the barrels they ordered. 

CENTCOM forces destroyed five Iranian crude oil carriers, Sept.
8, after the Islamic Revolutionary Guard Corps (IRGC) targeted a U.S.
Navy warship with ballistic missiles twice over the past two days.
The U.S.
warship successfully evaded the attempted Iranian attacks and… pic.twitter.com/Gi8a2tloN1

— U.S.
Central Command (@CENTCOM) September 8, 2026

 Links :

• Euro-Times : Container traffic through Hormuz collapses 94% as oil tankers return
• Reuters : Hormuz traffic below 10-day average, LNG vessels reappear outside strait 

Conor Maguire rides 60-foot monster wave at Mullaghmore Head

 Watch Conor Maguire surfing a 60-foot monster wave at Mullaghmore Head in County Sligo, Ireland. It is probably the biggest wave ever surfed in Irish waters.

Conor Maguire rehearsed this monster 1,000 times in his head
Conor Maguire released Barry Mottershead’s tow rope above what he later described as a 40-foot drop. One wrong line at Mullaghmore, he said, could have dragged him underwater towards the cliff.
The calm was trained.

 

For days, Conor pictured every step.
As the horizon turned black, Barry looked back and saw him with his eyes closed, breathing.
I’m amazed by how little Conor does once his line is set.
He stays low and avoids any needless movement that might waste speed or unsettle the board.
(That quiet is the loudest part of this ride.)
Mullaghmore is a reef slab.
Deep water meets shallow rock, the face rises sharply and a thick lip throws forward.
Nazaré’s canyon can build even taller peaks over shifting sand, but often with a broader face.
Here, the prize is a tight barrel with almost no room to adjust.
Huge respect for that whole team.
Serious big-wave surfing is never a solo stunt.
Could you stay that still beneath this much water?

Regent Viceroy Seaglider first flight

The Seaglider era has begun! This morning in Narragansett Bay, Rhode Island, the Viceroy Seaglider prototype, crewed by two captains, flew a distance of 1,956 ft (596 m) at a height of 33 ft (10m) above the water for 30 seconds.

‘World’s first’ crewed flying boat completes maiden flight: Regent Craft's Seaglider, a 12-passenger electric vessel that floats, hydrofoils, then flies just above the water using ground effect, carried two people for a 30-second test flight over Narragansett Bay.

Regent is pitching it as a new mode of coastal transport, with proposed routes already planned between cities like New York, Boston, Miami, and nearby destinations.