Hundreds of giant oil tankers have been anchored in the Persian Gulf for months after the energy crisis triggered by fighting with Iran. Now that the world expects oil flows to resume, a less obvious problem is delaying the restart: heavy marine buildup on the ships’ hulls, including mollusks, algae, barnacles, and other sea life.
The vessels need a costly, complicated cleaning before they can sail again. Specialized diver teams, described as bottom cleaners, must scrub each tanker’s underside, which is more than 300 meters long and about 45 meters wide, covering roughly 14,000 square meters. A crew of five to six divers spends about four to five hours per ship using hand scrapers and high-pressure wash systems.
The fouling is not just cosmetic. It significantly reduces fuel efficiency, making transport much more expensive, and crews must avoid damaging the vessels’ special anti-fouling coating, since that could trigger ecological violations. Propellers are especially difficult, and sometimes have to be removed, cleaned thoroughly, and reinstalled.
The sudden demand has pushed prices sharply higher, with cleaning teams now charging tens of thousands of dollars per ship. Even beyond the cleaning, the resumption of oil transit faces further hurdles: Iran says companies must register in the country to pass through the strait, and mine-clearance vessels are also needed to clear the route. Together, these obstacles are slowing the global oil market’s return to normal, starting unexpectedly with marine growth on the tankers.
