Why Saltwater Is One of the Biggest Enemies of a U.S. Aircraft Carrier

[00:00:06]The US Navy spends close to10 billion every single year fighting something that costs nothing and is found everywhere on Earth.

[00:00:15]It has no engine, no weapon, no crew. It does not fire missiles. It does not launch attacks, but it quietly eats through steel, destroys aircraft, ground fleets, and has forced the most powerful warships ever built into a dry dock.

[00:00:31]Sometimes for years, it is saltwater.

[00:00:35]And for a US aircraft carrier, a machine that costs over 12 billion to build, saltwater is not just an inconvenience.

[00:00:42]It is a relentless, invisible enemy working around the clock. Every single day, the ship is at sea. And here is what makes it truly alarming. Most people never even know the battle is happening.

[00:00:59]A US aircraft carrier is the most powerful and most expensive warship in human history. It carries fighter jets, nuclear reactors, and thousands of sailors. It projects American power to every corner of the world. But beneath the surface and on every single inch of that ship's hull, flight deck, aircraft, and systems, a slow, silent war is being fought against the very ocean those carriers sail on. Today, we are going to break down exactly how saltwater attacks a carrier, what it costs, and what the Navy is doing to fight back. This story involves billions of dollars, grounded fighter jets, and a problem that has been plaguing the US Navy for over 200 years. If you're a proud supporter of the men and women who keeps this nation's Navy strong, type proud in the comments below. Let us know you are here. Why saltwater is so destructive.

[00:01:54]Before we get into carriers themselves, let's talk about why saltwater is so uniquely dangerous to steal. Because most people think it is just regular water with a little salt in it. It is not. Salt water is one of the most chemically aggressive substances that the metal can come into contact with.

[00:02:10]Here is why. Salt water conducts electricity. When it touches steel, it creates what is called a galvanic reaction. Two different metals in contact with a salty liquid form a natural battery. One side of that battery acts as aid. And it starts to dissolve. That is corrosion. That is rust. And it happens faster than most people realize. But it gets worse. The ocean is not just salty. It is full of dissolved oxygen, biological organisms, temperature changes, and constant pressure and movement. Every one of those factors makes the corrosion worse.

[00:02:47]Warmer water speeds it up. Higher oxygen content accelerates it. Water moving at speed scrubs away protective coatings and opens fresh metal to attack. A US aircraft carrier operates in that environment every single day of its deployment, which can last anywhere from 6 to 9 months at a stretch. No other military machine on Earth is exposed to that kind of sustained all-around chemical assault. And the size of the problem is not small. The hole fighting in ocean from the outside. An aircraft carrier's hole is massive. We are talking about a ship that is over 1,000 ft long, displaces around 100,000 tons of water, and has a steel hole that goes roughly 36 ft below the surface.

[00:03:30]That entire underwater surface is in direct constant contact with seawater.

[00:03:34]The moment any part of that steel is exposed, a scratch, a crack, a patch where the coating has worn thin, the ocean gets in. And once it gets in, it does not stop. The Navy fights this in a few ways. First, protective coatings.

[00:03:49]The hull is coated with specially formulated anti-corrosion and anti-alling paint. These paints are designed to do two jobs. One, they create a physical barrier between the steel and the water. Two, they prevent sea life, barnacles, algae, organisms from attaching to the hull because when sea life grows on the hull, it holds moisture against the steel constantly, making corrosion dramatically worse. The Naval Sea Systems Command, known as NAVC, has been developing and updating these paint systems for over a hundred years.

[00:04:22]In December 2024, NAVC published an updated performance specification for ship hole paint systems, continuing a continuous effort to stay ahead of the corrosion problem. But paint is not enough on its own. Paint wears, paint cracks. Paint flexes when a 5,000 ton ship moves through heavy seas. When it cracks, seawater gets in. So, the Navy also uses a system called impressed current cathotic protection or ICCP.

[00:04:52]This is a system that runs a controlled electrical current through the hull. It works by reversing the electrochemical process that causes corrosion. Instead of the hole acting as the anoid, the piece that dissolves, the system forces it to act as a cathode, which is the piece that is protected. The Navy also uses physical sacrificial anoids, blocks of zinc bolted directly to the hull in the most vulnerable spots around the propellers, along the water line, near the rudder. These zinc blocks are designed to corrode instead of the steel. They sacrifice themselves so the hole survives. Those zinc blocks have to be replaced regularly. When they are gone, the steel becomes the next target.

[00:05:33]The cost of all of this, the coatings, the cathotic protection, the inspections, the replacements runs into hundreds of millions of dollars per carrier over its lifetime. And that is before we even talk about what happens above the waterline. The flight deck and superructure, the battle above the water. Most people think the danger from saltwater ends at the water line. It does not come close to ending there. A carrier at sea is surrounded by constant haze of salt spray, sea mist, and humid salt air. That salty air reaches every surfaces on the ship. The flight deck, the island structure, the hangar bay, the pipes, the wiring, the ventilation system, the doors, the ladders, everything.

[00:06:16]Salt does not need to be liquid to cause damage. Salt particles in the air settle on every surface and start drawing moisture from the air. That moisture combined with the salt starts the same corrosive process as direct contact with water. The flight deck alone is a unique battlefield. It is coated with special non-skid surface, a rough textured coating that allows jet aircraft to land safely. But that non-skid surface takes an incredible beating. jet exhaust, aircraft tires, arresting wire impacts, fuel spills, and constant saltwater exposure. When the non-skid wears down, the steel underneath is exposed. When the steel is exposed, it rusts. And a rusted or degraded flight deck is not just a maintenance problem. It is a safety problem. Aircraft operating off a compromised deck risk accidents.

[00:07:05]After an extended deployment, the flight deck must be completely stripped and recoded. That is not a quick job. It takes time, specialized crews, and expensive materials. When the USS Gerald R. Ford recently returned from an extended deployment, one of the major maintenance items listed was stripping and reapplying the flight deck's non-skid coating alongside hall corrosion treatment. The ship is expected to be in maintenance through 2027 or 2028 as a result. That is a year of downtime for one ship. Now, here is where the story gets even more serious, and a lot of people do not know this part at all. The saltwater problem does not just attack the carrier itself. It attacks every single aircraft sitting on that carrier. And those aircraft, the fighter jets, the helicopter, the support planes, those are worth hundreds of millions of dollars each. The damage being done to them while they sit on a carrier deck is staggering. The aircraft fighters being eaten alive at sea. When a carrier is at sea, the aircraft on the flight deck and in the hangar bay are living in what naval engineers describe as an extremely aggressive corrosion environment. Salt spray hits them constantly. The hangar bay is not fully sealed. It breathes with the ocean.

[00:08:16]Humidity levels are high around the clock and the aircraft cannot simply be moved somewhere safe and dry. They have to be ready to launch a moment's notice.

[00:08:25]And the aircraft cannot simply be moved somewhere safe and dry. They have to be ready to launch at a moment's notice.

[00:08:31]The FA18 Super Hornet is the Navy's primary carry-based fighter. It is the backbone of the carrier aviation and it has the highest total corrosion cost of any aircraft in the entire Department of the Navy. Between fiscal year 2017 and fiscal year 2020, the Navy spent over $2 billion dealing with corrosion damage specifically on the FA18 fleet. $2 billion in just three years on one aircraft type. The Navy's own expert described the situation this way.

[00:09:03]Corrosion is almost like a cancer. If nothing is done to stop it, it keeps going until it's too late to fix. That quote came from a Navy chemist who spent over two decades studying exactly this problem. But the Super Hornet is not the only aircraft under attack. The F-35C is the Navy's newest carrierbased fighter, a fifth generation stealth jet. Its stealth capability depends on a specially designed radar absorbing coating on its skin. If that coating is intact, the aircraft is largely invisible to enemy radar. If it degrades, the aircraft lights up. Here's what the Navy discovered when it began operating the F-35C from the carrier decks. The stealth coating degrades faster than expected. In the carrier environment, the salt air, the humidity, the heat from the flight deck, and the jet exhaust, all of it breaks down the coating at a faster rate than engineers originally planned for. The result, in one recent fiscal year, the F-35C's actual mission capable rate sat 51% below the aircraft's objective performance target, 51%. That means the Navy's newest, most advanced carrier jet was performing at barely half of where it needed to be. That is not a small problem. That is a readiness crisis. and saltwater is one of the primary drivers.

[00:10:18]The Fleet Readiness Center Southeast based in Jacksonville, Florida, has become dedicated repair hub for F-35 corrosion damage. When the aircraft goes in for corrosion repair, the standard turnaround used to take 180 days, 6 months per aircraft. Through dedicated engineering work, they reduce that to approximately 60 days. But even 60 days is 2 months of a fighter jet sitting out of service because of salt. the numbers what this is actually costing. Let's put this in plain numbers because the scale is hard to grasp. The Department of the Navy, which includes the US Navy and the Marine Corpse, spends an estimated $10 billion per year on corrosion. That number comes from Navy's own internal cost estimates adjusted for inflation for 2023.

[00:11:04]To put that in perspective, the USS Gerald R. Ford, the most expensive ship ever built, costs $12.8 billion to construct. The Navy spends nearly that much every single year just fighting corrosion across its fleet. Of that $10 billion annual bill, ships account for the largest single share, estimated at around $3.2 billion per year. Naval aviation comes in at over $3.7 billion per year. Marine Corps, ground vehicles, and facilities account for the rest.

[00:11:33]Corrosion alone accounts for more than 27% of all maintenance spending in the naval aviation. That means more than one out of every four dollars spent on maintaining Navy aircraft goes directly to fighting the effects of saltwater and the marine environment. The Department of Defense owned 2021 corrosion prevention and control strategy confirmed that corrosion maintenance generates 11 million hours of repair time and lost flight time annually across the Navy alone. 11 million hours every year.

[00:12:06]That is not just money. That is sailors working. That is aircraft sitting on a ground instead of flying missions. That is readiness being drained quietly while no one fires a single shot.

[00:12:20]Conclusion. The men and the women of the US Navy do something extraordinary. They take the most powerful warships ever built, machines that represent the best of American engineering and American resolve, and they sail them directly into the ocean's harshest conditions.

[00:12:34]Day after day, month after month, they fight the weather. They fight adversaries. And they fight an enemy that most people never think about. One that has no commander, no headquarters, and no agenda, but costs more than almost anything else the Navy faces.

[00:12:49]Saltwater. It is not glamorous. It is not in the news, but is one of the defining challenges of keeping a US carrier fleet ready to defend the nation. The next time you see footage of a carrier battle group underway, remember what is happening beneath the surface. Remember the sailors grinding rust. Remember the engineers developing codings and labs. Remember the maintenance crews working around the clock in shipyards across the country.

[00:13:14]They are all part of the same fight. And the fight never stops.