Ship bottoms are painted red because the most common antifouling ingredient, cuprous oxide, is naturally a deep red pigment. This copper-based compound has been the standard defense against barnacles, algae, and other marine organisms for over a century, and its reddish color simply comes along for the ride. The red isn’t a design choice or a tradition for its own sake. It’s the color of the chemistry that keeps hulls clean.

What Cuprous Oxide Actually Does

The underwater portion of a ship’s hull is constantly under siege. Algae, barnacles, mussels, tube worms, and dozens of other organisms try to attach themselves to any submerged surface. Left unchecked, this layer of growth (called biofouling) creates enormous drag. Studies estimate that biofouling can increase a ship’s fuel consumption by 5 to 15 percent, which on a large cargo vessel translates to millions of dollars in wasted fuel per year.

Cuprous oxide fights this by slowly dissolving in seawater and releasing copper ions. Those ions are toxic to marine organisms in several ways: they penetrate cell membranes, generate reactive oxygen species that damage cells from the inside, and disrupt the biological processes organisms need to attach and grow. When seawater interacts with cuprous oxide, it forms soluble copper chloride complexes that spread across the hull surface, creating a thin zone that’s inhospitable to settling larvae and algae spores. The paint is designed to erode gradually, continuously exposing fresh pigment so the protection lasts for years between dry-dock maintenance.

Why Red and Not Some Other Color

Cuprous oxide is inherently red to reddish-brown, much like rust (iron oxide) is inherently orange-red. Both are metal oxides, and their color comes from the way their crystal structure absorbs light. Since cuprous oxide is the most cost-effective and widely available antifouling pigment, and since it needs to be present in high concentrations to work, it dominates the color of the final paint. You can add other pigments to shift the shade, and some manufacturers do produce antifouling paints in blue, black, or green. But those formulations still contain copper compounds as the active ingredient, just masked by additional coloring. Red remains the default because there’s no practical reason to add extra cost changing the color of a surface that spends its life underwater.

Iron oxide, another cheap red pigment, also shows up in marine primers as a corrosion inhibitor. So even the base layers beneath the antifouling topcoat tend to be red or reddish-brown, reinforcing the association between ship bottoms and the color red.

A History of Toxic Solutions

Sailors have been fighting biofouling for as long as ships have existed. Early solutions included coating hulls with lime, tar, and even arsenic. Copper sheathing became popular in the 18th century, when the British Royal Navy began nailing thin copper plates to wooden hulls. The principle was the same one that modern paint relies on: copper dissolving slowly into the water to poison anything trying to grow.

In the 1960s, the chemical industry developed an extremely effective alternative: paints based on tributyltin, or TBT. These worked brilliantly at preventing fouling but turned out to be an environmental disaster. TBT persisted in the water long after leaching from hulls, accumulating in harbors and coastal waters. It caused shell deformations in oysters and induced sex changes in whelks, collapsing populations near busy shipping lanes. The International Maritime Organization adopted a convention banning TBT-based antifouling systems, requiring member nations to prohibit their use on all ships entering their ports, shipyards, or offshore terminals. That ban pushed the industry back toward copper-based paints, which are less persistent in the environment, and the familiar red bottom paint became even more dominant.

Modern Alternatives Are Changing the Palette

Not every ship bottom is red anymore. A growing number of vessels, particularly high-speed ferries and naval ships, use fouling-release coatings instead of traditional antifouling paint. These work on an entirely different principle. Rather than poisoning organisms, they create a surface so slippery that anything attempting to attach gets washed off by the flow of water as the ship moves. The most common versions are based on silicone elastomers, which have low surface energy (think of how little sticks to a silicone baking mat) and high elasticity. Because these coatings contain no biocide, they’re considered far more environmentally friendly.

Silicone-based coatings are typically white, gray, or translucent, giving hulls a very different look from the classic red. Some newer formulations combine silicone with hydrophilic polymers that attract a thin layer of water molecules, creating an additional barrier against protein adhesion, which is the first step in biofouling. Others incorporate compounds that kill organisms on contact without leaching chemicals into the water.

These coatings do have trade-offs. The same slippery surface that repels barnacles also makes it harder for the coating to bond to the hull, so adhesion failure and peeling can be problems, especially on vessels that spend long periods sitting still in port. For stationary or slow-moving ships, the water flow isn’t strong enough to dislodge organisms, so copper-based paints remain the more reliable choice. That’s why the vast majority of commercial cargo ships, tankers, and bulk carriers still wear red below the waterline.

The Waterline as a Maintenance Indicator

There’s one more practical reason the red color has stuck around: visibility. When a ship enters dry dock for maintenance, inspectors can easily see where the antifouling paint has worn thin because the primer or bare metal underneath shows through. A consistent, distinctive color like red makes wear patterns obvious at a glance. The waterline itself, where red antifouling paint meets the black or gray topside paint, also serves as a visual reference for loading. If the red paint is submerged too deeply, the ship is overloaded. If too much red is visible above the water, it’s riding light. The contrast between hull colors gives port authorities and crew a quick, no-instrument check on a vessel’s draft.

 Reference: Scienceinsights

Divergent Technologies, Mach Industries unviel Venom Autonomous Strike Aircraft

Two California defense startups designed, built, and flew a new rapid-build autonomous strike aircraft in just 71 days, a timeline that illustrates how quickly Pentagon-backed drone programs are evolving. 

Divergent Technologies and Mach Industries announced the first flight of Venom, a prototype unmanned aircraft developed using a fully digital design and additive manufacturing process. The companies say the project moved from concept to first flight in just over two months. 

Photos released following the announcement show US Secretary of Defense Pete Hegseth with company executives, a sign that the program has visibility at senior levels inside the Department of Defense. 

Mach Industries, founded in 2023 and based in Huntington Beach, California, led system architecture and integration. Divergent Technologies, headquartered in Torrance, California, and founded in 2014, designed and 3-D printed the aircraft’s structure using its Divergent Adaptive Production System. 

Rather than build the airframe from hundreds of individual parts, Divergent printed large monolithic assemblies, including wings, fuselage sections and control surfaces. The approach reduces part count and eliminates traditional tooling, which can slow aerospace production. 

The companies did not release detailed performance specifications for Venom. They described it as an autonomous strike aircraft and positioned it within the Pentagon’s push for “affordable mass,” a term used to describe large numbers of relatively low-cost unmanned systems that can be fielded quickly. 

That shift reflects lessons from Ukraine and other recent conflicts, where inexpensive drones have forced militaries to rethink how they defend against low-cost unmanned aircraft. 

Mach says it has taken four products from concept to flight test in the past 18 months and recently secured a production contract, though it did not specify the customer or dollar value. The company said it focuses on vertically integrating propulsion, weapons, and manufacturing to shorten development cycles. 

Divergent, which previously worked in automotive manufacturing before expanding into aerospace and defense, has raised significant capital to scale its digital production platform. The company said it plans to produce thousands of airframes annually using its additive manufacturing system. 

The companies say the program demonstrates how software-driven development can shorten production timelines while avoiding the need to create legacy manufacturing infrastructure. 

Whether Venom becomes a fielded system will depend on details the companies have not shared, including range, payload, autonomy and unit cost. For now, the 71-day timeline is noteworthy, and it appears to fit with the Pentagon’s desire for rapid production of simple, lower-cost weapons systems. 

Reference:ByStephen Pope February 17, 2026  

DUBAI, United Arab Emirates (AP) — Skyscraper-studded Dubai has been on a hot streak for the last five years — and some residents are starting to feel burned.

The city-state has seen record-breaking real estate transactions and as more and more people come to live there, and its state-owned airline Emirates is booking record earnings. But all that growth comes with strains for the city’s population.

Traffic feels worse than ever on Dubai’s roads. The price of housing continues to spike even with new real estate projects being announced almost daily. Caught in the middle are both its Emirati citizens and the vast population of foreigners who power its economy — sparking rare public expressions of concern.

“Dubai is on steroids but affordability risks are increasing,” warned Hasnain Malik in a starkly titled report he wrote for the global data firm Tellimer, where he’s a managing director.

Skyrocketing housing prices

Under Dubai’s current plans, the city aims to have 5.8 million residents by 2040, adding more than half its current estimated population in just 15 years. Since 1980, its population has already soared from around 255,000 to around 3.8 million.

Real estate lit the fire in Dubai’s growth in 2002, when the desert sheikdom began allowing foreigners to own property. After sharp falls during both the 2008-2009 financial crisis and Dubai’s brief coronavirus lockdown, prices have been soaring.

Today, average prices per square foot are at all-time highs, according to Property Monitor. Rental prices increased as much as 20% in key neighborhoods last year, with further rises likely this year, with some residents moving to communities further out in the desert, the real estate firm Engel & Völkers said.

Jammed roads

Even before the boom, some people who worked in Dubai chose to live in the neighboring emirate of Sharjah, some 20 kilometers (12 miles) north of the city’s downtown, or further away. Some 1 million commuters from other emirates jam the 12-lane Sheikh Zayed Road that runs through the center of the city and other highways every day, as studies suggest that as many as four out of five employees drive to work alone.

That traffic has only intensified with Dubai’s new arrivals.

While the rest of the world saw as much as a 4% increase in the number of registered vehicles in the last two years, the city’s Road and Transportation Authority says there’s been a 10% increase in the number of vehicles.

So many vehicles have been registered that the city has had to make license plates longer.

And while the city keeps building new flyovers and other road improvements, more cars are coming from more directions than ever before.

“Dubai is very attractive, more and more people are coming,” said Thomas Edelmann, the founder and managing director of RoadSafetyUAE, which advocates about traffic issues. “I think it’s easier to get people quickly to come to Dubai and to convince them about Dubai, then to build a new intersection or a new highway.”

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Boom concerns also raised by Emiratis

Congestion has got so bad that it’s driving even prominent Emiratis to break their customary silence on public affairs.

Habib Al Mulla, a prominent Emirati lawyer, wrote on the social platform X in December that while authorities were working on congestion, the problem demanded “a set of immediate and long-term mechanisms.” He followed up by publishing an opinion piece twice mentioning “congestion” as being among “pressing issues” for global cities like Dubai.

While phrased in mild language, Al Mulla’s comments represented rare public criticism in the United Arab Emirates, where speech is tightly controlled by criminal law and social norms favor raising issues at a “majlis” — a semiprivate setting convened by a traditional ruler.

“The concentration of wealth and opportunities created in global cities may cause income inequality that pushes out lower-income residents,” Al Mulla warned in the English-language Khaleej Times newspaper on Jan. 15.

“The problem becomes acute when the wealth and opportunities remain inaccessible to segments of the national population who witness the city’s allure being seized by outsiders. This may carry significant social risks, if not mitigated.”

Then there’s demographic concerns as the Emirati share of the population dwindles. While the number of citizens isn’t public, a back-of-the-envelope, informal calculation shared for years by experts suggests Emirati citizens represent around 10% of the country’s overall population of more than 9 million people, a number that’s likely falling as foreigners rush in.

In December, sermon scripts issued for the Dec. 13 Friday’s prayers directly touched on the duty of having more children.

“Increasing offspring is both a religious obligation and a national responsibility, as it contributes to the protection and sustainability of nations,” the sermon read, according to a transcript issued by the federal government’s General Authority of Islamic Affairs and Endowments.

A search for high-tech solutions

For Dubai’s autocratic government, overseen by ruler Sheikh Mohammed bin Rashid Al Maktoum, possible solutions to the grinding traffic have ranged from the practical to the fanciful. The government in recent months has repeatedly encouraged companies to allow more remote work options, including in a report released in November that also suggested staggered and flexible working hours.

Adding as many as five remote workdays a month, along with the other steps, “can reduce morning peak travel time across Dubai by 30%,” the study stated.

Dubai’s road toll system, known as Salik, has added gates to charge drivers more and will institute surge pricing at the end of the month. Dubai’s Metro, which boasts the world’s longest self-driving rail line, will also grow beyond its broadly north-south routes in a nearly $5 billion expansion.

Then there’s the flying taxi project. Since 2017, Dubai has been announcing plans for airborne cabs in the city. A first “vertiport” is being built by Dubai International Airport with the aim of offering the service from next year.

Dubai also plans 3,300 kilometers (2,050 miles) of new pedestrian paths, although during Dubai’s summer months pedestrians have to contend with high humidity and heat of around 45 degrees Celsius (113 degrees Fahrenheit).

“In the coming years, residents of Dubai will be able to move around by walking, cycling, its extensive network of roads and bridges, the Metro and its new lines, water taxis, or flying taxis on specific air routes,” Sheikh Mohammed said on X in December.

But for now, Dubai keeps attracting more people and more cars — and the traffic jams only get longer.

Reference: Jon Gambell: APNNews

The Strait of Hormuz