(dramatic upbeat music) (birds chittering) [Narrator] For thousands of years, the ocean has called us, a vast, uncharted expanse that challenges the boundaries of our imagination and engineering prowess.

Today, as much as ever, the sea inspires innovation and ambition.

(dramatic upbeat music) From colossal cargo ships and luxurious cruise liners, to autonomous vessels of the future, maritime engineering has revolutionised our relationship with the sea.

(dramatic upbeat music) As we sail towards the middle of the 21st century, the endless horizon remains a nexus where human ingenuity meets the unknown.

It propels us forward in our quest to master the world of water.

(dramatic music) (air whooshing) (upbeat music) 70% of the Earth's surface area is water.

For humanity to progress, we had to invent ways to conquer it.

With each voyage and innovation, we developed more communities and infrastructure where the sea connected to the land.

Port cities developed vibrant, multicultural populations, thanks to the constant flow of sailors, traders, and immigrants.

Maritime professions such as sailors, fishermen, and dockworkers, formed distinct cultural identities and traditions, contributing to the social fabric of coastal regions.

(upbeat music) But it wasn't just the movement of people that was so significant.

The movement of goods has completely transformed the standard of living for billions around the world.

But before we had the immense ships to carry our cargo around the globe, we had to be more inventive.

Ancient Egyptians transported goods and materials up and down the Nile, It was a significant part of the advancement of the region's civilization.

Vikings used swift revolutionised for raids, while Knarr cargo ships carried goods like spices, metals, and furs, fostering cultural exchange.

During the European Age of Discovery, caravels and galleons emerged.

These iconic vessels forged global trade routes between Europe, the Americas, Africa, and Asia, completely transforming humanity.

(water sloshing) New cultures were introduced.

(spirited upbeat music) (air whooshes) New materials were used for clothes, furniture, and art.

And of course, new delicious tastes evolved distinctive local cuisines.

(spirited upbeat music) It was an era where unimaginable exotics appeared on the azure horizon, before docking at the port, and making their way to markets and people's homes.

And the country at the centre of it all, Portugal.

Portugal is a nation of maritime pioneers, with a history intertwined with the sea, celebrated through its preserved buildings and maritime museums, attracting tourists worldwide.

Located on the Iberian Peninsula in Southwestern Europe, Portugal is renowned for its picturesque landscapes, beautiful architecture, and rich cultural heritage.

(spirited upbeat music) But one Portuguese port sits at the epicentre, even named for its purpose, Porto.

(spirited upbeat music) (birds chittering) The country's second-largest city sits where the Douro River meets the Atlantic, and has been instrumental in Portugal's maritime dominance.

It was the Romans in 138 BCE, who established the area as a trading post and named it Portus Cale.

It was strategically built to connect the Atlantic to Rome, facilitating the movement of goods, troops, and information.

(spirited upbeat music) (water sloshing) During the Age of Discovery, this vibrant port served as the launching pad for explorers and traders.

Local shipbuilders crafted vessels capable of withstanding long, treacherous journeys.

(dramatic music) Ships laden with goods and dreams departed from Porto, expanding the Portuguese empire as they went.

The riverfront was lined with warehouses, shipyards, and merchants' houses, employing countless people in ancillary trades, such as rope makers and coopers.

The port itself needed an enormous workforce to handle the bustling activity, thousands of sailors, dockworkers, shipbuilders, and carpenters undertaking long hours of physical labour.

(dramatic music) Then at the start of the 18th century, England went to war with France.

And as a country of wine lovers, the English needed to keep their palates satiated without relying on French wine.

Portugal's long history of wine making and friendly trade relationships made it the perfect choice.

But to withstand the long journey by sea to England, Portuguese winemakers added brandy to their product.

This process of fortification not only preserved the wine, but also enhanced its flavour.

It was a rich, sweet, robust, and tasty strategic alliance, born from wartime necessity, and established port wine as one of Portugal's most iconic exports.

(dramatic upbeat music) Porto was a crucial node in the burgeoning global trade network.

It literally opened Europe up to the rest of the world.

(dramatic upbeat music) The trade network grew so large, so quickly, that our world of water needed laws and regulations to govern trade practises, dispute resolutions, and the conduct of sailors and merchants.

Portugal developed these frameworks which influenced maritime law in other European countries, and many are still relevant today.

Throughout the 18th and 19th centuries, the port underwent significant modernization.

Dredging the Douro River allowed larger ships to navigate more easily.

Quays and piers accommodated more vessels and facilitated loading and unloading.

But as the 20th century approached, it was clear the port of Porto would not have the infrastructure needed for the new age of sea trade.

The new, larger, modern Port of Leixões was established just nine kilometres northwest of Porto's centre.

Continuing Porto's centuries-long tradition of sea trade, the Port of Leixoes is a state-of-the art hub of activity.

Its strategic location and advanced shipping technology sees more than 3,000 ships call at the port, with more than 18 million tonnes of cargo.

The economic value of sea trade is immense.

(birds chittering) (water sloshing) Throughout history, wherever something holds value, it inevitably attracts the attention of others who seek to claim it.

(bright lively music) (air whooshes) India, long regarded for its vibrant culture, was even more coveted for its wealth of natural resources, making it a prime focus for European powers.

(engine purring) In the Southwest, Kerala became a hub for the spice trade, drawing traders from Europe, the Middle East, and beyond.

(spirited upbeat music) The 16th century saw the Portuguese seize control of Kerala's key port, Cochin, followed by the Dutch in the 17th century.

By the 18th century, a new global power recognised India's potential, a nation eager to exploit its resources and strategic position, thus began a defining chapter in India's history, British colonisation.

(dramatic upbeat music) It was an opportunity to expand the British Empire, and over the following decades, Britain gradually tightened its control over India.

Extensive trade networks were established using India's ports to export raw materials to Britain and import finished goods, fueling the Industrial Revolution back home.

(spirited upbeat music) Today, Kerala is famed for its serene backwaters, Its location on India's south-western coast gives it access to rich fishing grounds, making it one of India's premier suppliers of seafood.

But as the Industrial Revolution gained full steam, Port Cochin was transformed into a linchpin in global trade.

Its spices attracted merchants from Europe, the Middle East, Asia and beyond, making it a bustling cosmopolitan centre, evidence of which is still seen all around the town in its architecture.

But the area's multicultural past goes back even further.

Chinese fishing nets are believed to have been introduced to the port by Chinese explorers in the 14th or 15th century, and use large, cantilevered nets operated by a team of fishermen.

They lower the net into the water and raise it using a system of weights and counterweights, capturing fish as the net emerges.

(dramatic upbeat music) British exploitation of India's resources and people led to economic drain and social upheaval.

Colonial policies prioritised British economic interests at the expense of local industries and livelihoods, leading to widespread suffering and resentment.

But despite its tumultuous past, India regained independence in 1947.

Infrastructure developed, and India became a powerhouse in the global economy.

In the 2023-24 financial year, Port Cochin set a new record by handling 36.32 million tonnes of cargo, more than 3% higher than the previous year, and more than 1,500 ships.

The port also attracts numerous cruise ships each year, boosting Kerala's tourism industry.

And its recent sustainability initiatives like solar power infrastructure, for ships to connect to while docked, will help the port reduce its environmental impact.

Since the Industrial Revolution, continual innovations in seafaring and the handling of cargo through the modern world's mega ports have completely transformed how our world of water works.

Globalisation and the reliance on international trade by sea are irreversibly integrated into our systems, routines, supply chains, and technology.

(dramatic music) Belgium in Western Europe is home to one of the most important mega ports in the world.

(dramatic music) The city of Antwerp sits on the mighty River Scheldt, the ancient waterway that's been the site of beautiful art and horrific battles throughout human history.

With its estuary at the North Sea, the river is navigable by large ships more than 80 kilometres inland into Europe, where they arrive at the Port of Antwerp.

(spirited upbeat music) Napoleon Bonaparte ordered the construction of Antwerp's first lock and dock in 1811.

More than 200 years later, the Port of Antwerp has evolved into Europe's second-largest port.

The scale is incredible.

It covers an area of 130 square kilometres, handles more than 240 million tonnes of cargo every year, and links to a remarkable 200 destinations in North Africa and Europe.

It also boasts the world's largest dock lock, the Kieldrecht lock and the Vrasendock, which stretches approximately 4.5 kilometres.

(spirited upbeat music) It's a marvel of engineering and logistics, with a distinctive headquarters.

The Port House's angular glass facade, perched atop a historic fire station, reflects the city's rich maritime heritage while the building's striking iceberg-like structure on top, speaks to the port's future-focused approach to international sea trade.

(spirited upbeat music) Ports like Antwerp are the epitome of globalisation, and vulnerable bottlenecks in the world's supply chain.

Anti-globalization protests can cause havoc, but so can other socio-political upheavals.

When the UK voted in favour of Brexit, the Port of Antwerp had to prepare for increased customs checks, delays, and administrative burdens.

Just a few years later, globalization's fragility was on display again when COVID-19 struck the world.

The port saw a massive 4.9% decline in cargo volumes.

(spirited upbeat music) But existing advances in automated container terminals proved effective in the face of the pandemic.

At some terminals, automated vehicles and robotic cranes handle the majority of cargo operations, reducing the size of the human workforce.

(spirited upbeat music) But it's not the first time the Port of Antwerp has gone through a substantial transformation.

The port was heavily bombed during World War II, devastating the city and its sea trade infrastructure.

(dramatic music) And in 1944, the Battle of the Scheldt was a crucial operation to clear German forces from the river's estuary, enabling Allied access to the Port of Antwerp.

(bright lively music) Subsequent rebuilding wasn't just about returning the port to normal, it was about proving Europe's resilience and determination to recover and thrive.

It is a symbol of how European societies, once ravaged by conflict and war, have united in peace and cooperation to become a major player in global peace and economic stability.

(dramatic music) (spirited upbeat music) A port may be where a ship's journey ends, but it's most likely just the start for the people and goods onboard.

From an era well before trucks, trains, and cars, a system was needed to move efficiently around towns and cities, and into landlocked countries.

Canals are not just incredible feats of engineering, they are symbols of human ingenuity, beauty, and history, the catalyst for societies to thrive.

They have played a crucial role in inland navigation, allowing goods and people to travel efficiently across great distances.

And in some cases, canals connect distant oceans by literally cutting through continents.

(birds chittering) (upbeat music) (air whooshes) In Egypt, vibrant culture meets ancient mystery.

(upbeat music) It's renowned for bustling cities, food markets, iconic pyramids, and the timeless Nile River.

It also used to be physically connected to Asia.

The concept of creating a channel between the Red Sea and the Mediterranean dates back to ancient Egypt, where the first implementation of a canal was undertaken.

But it wasn't until 1869 that the Suez Canal filled with water, a monumental achievement under the leadership of French diplomat, Ferdinand de Lesseps.

At more than 190 kilometres long, the canal required the complete reimagining and transformation of the geography of the region.

Carving the canal from the desert sands took approximately 10 years, relying heavily on forced labour.

Tragically, tens of thousands of labourers died, many succumbing to cholera and other epidemics.

The construction of the canal is estimated to have had a total workforce of over 1.5 million from multiple countries, and more than 30,000 workers on site at any given time.

But, it's the thousands of kilometres the canal cuts from trade routes between Asia and Europe that make it one of the biggest shortcuts ever built.

It eliminates the need for ships to navigate around Africa's southern tip, at the Cape of Good Hope.

The 21,000 kilometre, 24-day journey from the Persian Gulf to Northern Europe was reduced to 12,000 km and just 14 days.

Today, about 12% of the world's trade passes through the Suez Canal, underscoring its critical role in international commerce.

In 2022 alone, over 22,000 vessels traversed the canal, an average of around 60 per day.

But of course this means if something goes wrong in the canal, the impact is massive.

(spirited upbeat music) In 2021, the Suez Canal faced a major obstruction when the Ever Given, one of the largest container ships in the world, ran aground and blocked the canal for six days.

The incident halted billions of dollars' worth of trade and caused significant delays in global supply chains.

Over 360 were stranded, including container ships, oil tankers, bulk carriers, and other vessels, all waiting to pass through the canal.

As a result, the canal is being widened and deepened.

And additional passing lanes are being introduced to reduce the risk of future blockages, making the Suez one of the widest canals on Earth.

But in our interconnected world of water, the canal is a transportation marvel that comes in all shapes and sizes.

But just as the scale of the Suez is intense, the intimacy of Venice's famed canals make it iconic for entirely different reasons.

(spirited upbeat music) The stories contained in its piazzas, cathedrals, and art have developed Venice's reputation as one of the most romantic cities on Earth.

(gentle upbeat music) But at the core of Venice's allure, its canals.

They have defined the city's breathtaking charm for hundreds of years.

(gentle upbeat music) Gondolas and vaporettos navigate the historic waterways, offering a glimpse into the city's storied past.

(bell chiming) (dramatic upbeat music) Founded in 421 AD, Venice developed its canal system out of necessity.

(dramatic upbeat music) Built on a lagoon, buildings were constructed on its 118 small islands.

Some of the canals were created to manage water flow and to be used for transport, but many of them are the original natural waterways that fell between the islands, widened and deepened for better access.

Around 150 canals form the winding liquid streets of Venice, connected by bridges and walkways.

And the grandest of them all is, of course, Canal Grande.

(dramatic music) On an average day, hundreds of boats navigate up and down this iconic waterway lined with buildings that were mostly built from the 13th to the 18th centuries.

(dramatic music) The subject of countless artworks and stories, it's Venice's main road, and its heart.

During the Middle Ages, the canals were a major part of Venice's dominance as a serious maritime power.

They allowed goods and people to move efficiently within the city, which was crucial to keep Venice's workshops and marketplaces stocked and bustling.

The wealth generated from trade allowed Venice to invest in glorious Renaissance architecture, further enhancing its status.

The waterways also provided safe harbour for Venice's formidable naval fleet, which was crucial for expanding its political clout across the Mediterranean and beyond.

The city became a powerful republic with a complex and effective government that could wield significant influence in European politics.

Venice's uniqueness as a canal city built on a lagoon may prove to be its greatest threat.

Climate change is putting its historic buildings at risk.

Sea levels are rising, and Venice is sinking.

Extensive efforts are being made to protect Venice from going underwater.

The Modulo Sperimentale Elettromeccanico, or MOSE system, consists of 78 mobile barriers that can be raised to block high tides from flooding the city.

(water sloshing) (upbeat music) These barriers, installed at the inlets of the Venetian Lagoon, rest on the seafloor when not in use.

When storm surges threaten, compressed air is pumped into the barriers, causing them to rise and create a temporary wall that separates the lagoon from the Adriatic Sea.

Since its first use in 2020, MOSE has prevented numerous flooding events from inundating Venice.

Other projects focus on reinforcing canal walls, restoring salt marshes to buffer storm surges, and installing pumps and drainage systems to manage water levels.

The city is also exploring sustainable urban planning, raising the ground level of critical areas, and collaborating with international experts to address long-term climate resilience.

Hopefully these efforts mean Venice's canals can continue to transport commuters, trade, and tourists with delightful nostalgic charm for many years yet.

(bright lively music) (air whooshing) (bright lively music) The long-term success of Venice's canals influenced urban planning and architecture in cities around the world.

(bright lively music) Amsterdam is a cosmopolitan city in the Netherlands with a rich history and cultural scene.

(bright lively music) Its striking architecture, lively arts, and progressive laws embody Dutch personality and creativity.

But the city is also around two metres below sea level, putting it at risk of devastating flooding.

Unlike Venice, whose canals emerged from natural geography, Amsterdam's canals were meticulously designed to enhance trade and manage its water risks.

The city's canals are arranged in an unusual concentric ring pattern known as the "Grachtengordel."

Constructed in the 17th-century, the canals were an innovative urban project, meticulously designed to integrate residential, commercial, and defensive needs, and they played a pivotal role in Amsterdam's rise as a global trade centre.

(upbeat music) The canals were cleverly designed to control water levels and provide transportation routes.

This was crucial for a city built on marshy, low-lying land.

(upbeat music) The construction involved extensive land reclamation and the building of dikes and sluices to manage water flow.

(upbeat music) But the designers didn't just want the canals to be useful.

They wanted the canals to be part of the city's charm, to provide a foundation for the city's distinctive architecture, and the narrow, gabled houses lining the waterways.

But these days, some of the boats don't seem to have anyone onboard, not even a captain.

Remarkable autonomous "Roboats" may someday become a common sight in Amsterdam.

The self-driving vessel senses its surroundings, and if there is another boat or obstacle in the area, it will steer around it.

Roboats can collect waste, deliver goods, and transport tourists around the city.

(dramatic music) But whether being propelled autonomously, by old fashioned paddling, or strolling alongside the waterways, the heritage of the city and its innovative history lies in its lifeblood, the water flowing through the canals.

(dramatic upbeat music) There's a timeless romance to travelling on water, (dramatic upbeat music) where the gentle rocking and endless horizon evoke a sense of adventure, tranquillity, and reflection.

Some ships transcend their duty as a mere means of transportation to become something more.

Ferries are marvels of transportation.

They seamlessly connect distant shores and bustling cities.

They navigate rivers, lakes, and oceans, carrying people, vehicles, and goods.

They are efficient, adaptable, and are eco-friendly transit solutions that become part of landscapes.

Ferries have connected communities across bodies of water for centuries.

They carry commuters in bustling cities and cars across remote waterways, and take modern adventurers to some of the most breathtaking places in the world.

(dramatic upbeat music) On the other side of the world, Sydney, Australia, is a vibrant metropolis known for its iconic landmarks and beautiful beaches.

It's a global city with a dynamic economy, multicultural population, and situated on one of the world's most beautiful natural harbours.

Also known as Port Jackson, Sydney Harbour has been a key feature of Sydney's development since the 18th century, serving as a major port and gateway for exploration, trade, and colonisation.

In the early days of Sydney's expansion, journeys between distant suburbs and the emerging city centre, were made by horse-drawn carriages and drays which were slow and impractical.

A few small ferry services ran from the late 1700s but they were slow and susceptible to weather.

But the speed picked up in 1831, when the first Australian-built, steam-powered ferry commenced a regular passenger service between Sydney Cove and Parramatta.

Sydney's ferries are an iconic part of the city's transportation network, navigating long, winding waterways, and offering a unique way to experience the beauty of the harbour.

(dramatic upbeat music) The ferries still provide vital commuter links and are celebrated for their efficiency.

For over one hundred years, Sydney's expansive network of ferries has been a highly practical solution to answering the harbour cities unique public transportation challenges.

But the scale of Sydney's transportation needs pales in comparison to the tyrannies of distance faced by another nation of islands.

(spirited upbeat music) The Greek Islands are renowned for their stunning landscapes and rich culture.

(spirited upbeat music) Their strategic position, scattered across the Aegean and Ionian Seas, relies heavily on shipping for economic vitality.

(spirited upbeat music) Ports like Piraeus and Thessaloniki handle millions of tonnes of cargo annually.

Of Greece's 6,000 islands and islets, only around 227 are inhabited.

And they are connected to one another by an incredible fleet of ferries.

They navigate narrow straits, over often challenging waters, (upbeat music) (water sloshing) linking popular islands like Santorini, Rhodes, and Mykonos.

Greek Island ferries operate over 250 routes, moving 35 million passengers and 149 million tonnes of goods every single year.

The network has an essential role in Greece's economy too, estimated at around 7.4% of the country's gross domestic product.

Some of these modern ferries exceed 150 metres in length, and are engineered to carry up to 2,500 passengers and 700 vehicles.

They are high tech and high speed.

Larger vessels make use of powerful 30,000 horsepower engines, and catamarans zip around at 40 knots.

The extensive network is not just practical, they play a significant role in preserving Greek culture and reflect Greece's enduring connection to the sea.

(spirited upbeat music) From the earliest stone arches to modern steel and concrete giants, (spirited upbeat music) bridges have served as vital links between lands and cultures divided by water.

They conquer rivers, even oceans, seeming to defy gravity.

(spirited upbeat music) They are more than mere structures, they are lifelines that have transformed societies, bringing people closer together, enabling progress.

(spirited upbeat music) Bridges symbolise connection and innovation, standing as testaments to human creativity.

The history and stories that bridges hold are woven into the fabric of our civilization.

Bridges come in all kinds of forms, from beam bridges, arch bridges, suspension bridges, and cable-stayed bridges.

And when crossing water, they essentially have one job to do.

(upbeat music) (air whooshes) (upbeat music continues) But the Dutch have built an incredible series of bridges that have been engineered to do two very important jobs simultaneously.

(upbeat music) The Netherlands is known for its windmills and tulip fields.

But with its name literally translating as "lower countries," much of its land lies below sea level.

So water management is a matter of survival.

As cars zip along innocuous North Sea bridges, drivers are often unaware of the incredible engineering operating beneath them.

The Dutch have long battled the North Sea's encroachment, with devastating floods periodically taking lives and livelihoods.

The small town of Veere experienced it first hand in 1953 when it was terribly affected by the North Sea flood which inundated large areas of the country and claimed 1,836 lives.

(dramatic upbeat music) The disaster prompted the creation of the Delta Works, an ambitious system of bridges that also doubles as dams, sluices, and locks which act as massive storm surge barriers to hold back the sea.

The Delta Works is the largest flood protection system in the world.

Nothing like it had been attempted before.

Completed over several decades, these structures not only prevent flooding but also regulate water flow and salinity levels, safeguarding both people and agriculture.

Unlike traditional dams, some parts of the Delta Works, like the Oosterscheldekering, are designed to allow tidal movements, preserving the natural ecosystem while providing flood defence.

(spirited upbeat music) And the system is constantly monitored and maintained, with ongoing upgrades to adapt the system to rising sea levels.

(water sloshing) In 2007, a North Sea storm temporarily suspended maritime traffic in Rotterdam.

Authorities activated the massive Maeslant storm surge barrier.

It was the first time since its completion in 1997 that the barrier closed due to the high tide.

It took an hour and a half for the two doors, spanning a channel 360 metre wide, to shut, but was successful in limiting the effects of the surge.

The Delta Works continues to be a critical line of defence, bringing peace of mind for those behind its barriers.

Without it, the Netherlands would have experienced numerous devastating floods like the tragedy in 1953, which would only have increased in frequency and severity as climate change takes hold.

(bright lively music) Water and skylines seem to go together.

(bright lively music) New York City.

(bright lively music) Hustle, bustle, traffic, commerce.

Five boroughs separated by iconic waterways, The Hudson, New York Harbour, and East River, the tidal strait that once presented a formidable barrier between the boroughs of Manhattan and Brooklyn.

Crossing the river by boat was slow and often crowded.

(bright lively music) Today, they are connected by the one and only Brooklyn Bridge, (spirited upbeat music) the vital artery that carries cars, trucks, cyclists, and pedestrians 41 metres above the water below.

The bridge's Gothic arches stand over 35 metres above that, and together with intricate steel cables, is a marvel of both engineering and artistry, captivating the eye with its soaring lines.

Completed in 1883, it was the longest suspension bridge in the world, spanning 486 metres between its massive stone towers.

But construction was fraught with challenges.

The bridge's foundations were built using caissons, massive wooden boxes filled with compressed air, allowing workers to excavate underwater.

The bridge's Chief Engineer, Washington Roebling, fell ill from caisson disease.

Also known as 'the Bends', it's caused when people decompress too quickly and nitrogen bubbles form in the bloodstream.

Roebling's wife, Emily Roebling, took over the leadership role.

It was highly unusual for a woman to serve as a chief engineer, but she supervised the project to its completion, and was even the first person to cross it.

The bridge transformed the city's dynamics.

It provided a direct and reliable route that supported the city's rapid growth and economic development.

It also unified the boroughs, which strengthened the city's identity.

Over 4,000 pedestrians and 3,100 cyclists cross the bridge's elevated boardwalk each day, and more than 120,000 vehicles use the bridge's roadway.

In 2008, the bridge celebrated its 125th anniversary.

Not too many roads have birthday parties.

It showed just how much New Yorkers love their Brooklyn Bridge.

(fireworks popping) (dramatic upbeat music) (cars honking) (dramatic music) On the other side of the country, a vibrant and progressive city, renowned for its steep streets, diverse culture, and historic cable cars basks in the sunshine of California's Pacific coast, San Francisco.

(dramatic music) The northern tip of the city is separated from Marin County to the north by a 1.6 kilometre wide strait known as the Golden Gate.

During the last Ice Age, when sea levels were considerably lower, the waters of the glacier-fed Sacramento River and the San Joaquin River carved a deep channel in the bedrock on their way to the Pacific, creating the waterway.

The waters of the Golden Gate hindered travel and trade, until the Golden Gate Bridge conquered them.

Often shrouded in mist, the bridge is recognised worldwide for its distinctive orange colour and art deco design.

Constructed during the Great Depression, the bridge is a marvel of engineering, using flexible steel cables and a unique suspension system that can withstand powerful winds and earthquakes.

When it opened in 1937, it held the title of the world's longest suspension bridge, with a main span of 1,280 metres, easily bridging the strait below.

The bridge's towers broke records at 227 metres tall.

(dispatcher speaking faintly) (siren wailing) When a 7.1 magnitude earthquake hit the region in 1989, causing 63 deaths and at least 3,757 injuries, the Golden Gate Bridge remarkably showed no signs of damage.

But the quake highlighted its vulnerability.

So the bridge underwent seismic retrofitting.

(dramatic music) Meticulous maintenance and ongoing upgrades ensure the beloved orange icon will carry people across the Golden Gate strait for decades to come.

(dramatic upbeat music) The Sydney Harbour Bridge is an internationally-recognized symbol of Australia.

Its majestic steel arches span the harbour, connecting the bustling CBD with Sydney's North Shore.

Its distinctive shape inspired its nickname, "The Coathanger."

(dramatic music) (gentle music) But its origins came in the early 20th century as Sydney's population boomed.

The cross-harbor journey by ferry could be slow and unreliable, often disrupted by weather conditions.

The crossing was the perfect candidate for a bridge of significance.

(upbeat music) Construction started in 1923.

The concrete piers went up in 1926, and work began on the bridge's revolutionary double-hinged arches, that could expand and contract with changing temperatures.

Four years later, the arches touched for the first time.

It was a serious feat of engineering.

(upbeat music) (birds chittering) Construction of the bridge required over 52,800 tonnes of steel, and the efforts of thousands of workers.

(workers chattering) (upbeat music) Sadly, 16 men died on the bridge during construction, and incredibly, at least one man survived a fall into the harbour below.

In 1932, nine years after the first sod was turned, the bridge was officially opened, but not without incident.

Irish-Australian soldier, Captain Francis De Groot, atop a horse, slashed the ribbon with his sword, beating the Premier to the task.

De Groot was quickly escorted away by police, the ribbon was re-tied, and the Premier cut it again, declaring the bridge officially open.

It was the world's widest long-span bridge at the time, and the tallest steel arch bridge, stretching 1,149 metres, with an arch rising 134 metres above sea level.

It took 272,000 litres of paint to give it its first three coats.

And it's so iconic, it's a powerful platform for large scale marches and protests.

On 28 May 2000, a quarter of a million people walked across the bridge to show support for reconciliation.

Australian and Aboriginal flags flew side by side on top of the bridge's arch, while a skywriter wrote the word "Sorry" above.

In 2019, Greenpeace activists scaled the bridge to hang banners calling for action on climate change.

Today, the Sydney Harbour Bridge remains a remarkable structure, connecting communities and commerce.

It handles over 160,000 vehicles daily, supporting eight lanes of road traffic, two railway tracks, a pedestrian walkway, and a cycleway.

Ascending the Sydney Harbour Bridge is a breathtaking journey above the city's heart.

With each of the climb's 1,332 steps it takes to reach the Summit, the hum of the city fades further away, replaced by the breeze, and stunning 360-degree views.

The Sydney Opera House glistens below, and the harbour sparkles in the sun.

Over four million people have climbed the bridge, making it the most climbed bridge in the world.

It's a breathtaking way to get up close and personal with this enduring symbol of Sydney's and Australia's spirit and progress.

(spirited upbeat music) 71% of the Earth's surface is water, and the future holds exciting developments for the way humanity works with it sustainably.

Autonomous shipping is revolutionising the shipping industry, promising safer and more efficient operations with less human intervention.

The digitization of ports and growth of small ports are streamlining global trade.

Electrification is transforming ships into cleaner, more sustainable vessels, reducing emissions and protecting our oceans.

The China Belt and Road Initiative is one of the most ambitious infrastructure and investment projects in history.

This 21st Century Maritime Silk Road connects China to Southeast Asia, Africa, and Europe via new maritime trade routes.

But humanity's association with the sea is more than economics and trade.

While those before us put their lives at risk to map the oceans, we are still explorers at heart.

From lavish ocean liners to luxury cruises, to Antarctica and beyond, the seas continue to captivate and connect us.

The marvels of the past inspire us, while the promise of the future propels us forward on a voyage of discovery of our world of water.

(spirited uplifting music) (spirited uplifting music continues) (spirited uplifting music continues)