Rust is the result of a chemical reaction between air, water and iron, a major component of steel. Considering the fact that ships soak in salt water all day and night, corrosion takes place very quickly. Corrosion can cause the body of ships to deteriorate, destroy tanks, collapse hulls and cause motors to fail, according to CPV. Worst of all, there's no way to fully eradicate it; all you can do is stay vigilant.
"Ships are full of saltwater systems, they're full of salty ocean air," said Scott Tait, a retired Navy captain in an interview with the Los Angeles Times. "Corrosion through the entire ship is a huge, huge issue."
In the U.S. Navy and cruise industry, rust and corrosion are dealt with professionally. There are even special organizations and conferences dedicated to rust's existence and suppression, says the Times. MegaRust is an annual conference on the latest corrosion-fighting techniques and tech. Drawing in hundreds of professionals every year, live demonstrations of sandblasters and even lasers highlight the event.
In case the rusting issue wasn't big enough to begin with, rust prevention has its own set of consequences. Ships undergo maintenance at dry docks, special high-walled facilities where they're lifted up and out of the water. According to the Times, Navy ships ships used for freight transport typically go to a dry dock every five to seven years for repairs and maintenance. Issues arise for ships that carry commercial cargo when every day spent in dry dock is a day not spent bringing in revenue. However, maintenance is crucial. Ships which go extended periods of time without it are significantly more likely to develop corrosion problems on the waterline. Ignoring rust can create irreversible problems in just a few years.
"It's kind of a double whammy," said Lars Robert Pedersen, deputy secretary general of BIMCO, an international shipping trade association, in an interview with the Times.
Bradley Martin, senior policy researcher at Rand Corp. and a retired Navy captain added, "If it's not dealt with, the cost of going back and trying to correct things that should have been dealt with early can become exorbitant."
One of the most effective ways to prevent and control ship corrosion is to apply coatings to parts that are most susceptible to corrosion, says CPV. To delay the process of corrosion, the Navy uses paints designed to discourage rust on every part of the ship which is exposed to water. On the bottom of ship hulls, a special epoxy-based red paint is used to prevent rust and limit barnacle growth.
Rust is a brand and marketing issue as well as a maintenance issue for the cruise industry. A single rust carbuncle can bleed down the side of an ocean liner and leave an ugly vertical stripe. The red-orange stripe stands out especially strikingly against the crisp, white paint of the ship. In an industry that makes so much of its money on selling a vision to their customers, this cannot be allowed to happen. That's why cruise ships have a virtually ongoing effort to spot and stop rust and degradation before it becomes a visible issue.
Dealing with rust is an expensive, time consuming and physically demanding task. Newer ships are being designed with corrosion in mind from the start, so the demands of maintenance will at least be somewhat reduced down the line. Some new Navy ships have a brick of zinc mounted to bare metal to act as a sacrificial anode, and some ships are being built from fiberglass, says the Times. However, despite best efforts, no ship is immune from rust.