Ideally, the sea forgets nothing, but it forgives slowly. Few events scarred the Mediterranean maritime history like the sinking of the MT Haven. On April 11, 1991, the supertanker (VLCC), loaded with 144,000 tons of crude oil, exploded and caught fire off the coast of Genoa. After burning for three days, the massive vessel broke in two and sank off the coast of Arenzano, causing the largest oil spill in the history of the Mediterranean Sea.
For nearly two decades, the wreck lay on the seabed at a depth ranging from 33 to 80 meters. While it quickly became a haven for marine life, it remained a ticking environmental time bomb, holding hundreds of tons of solidified oil and bitumen trapped within its twisted hull.
The Challenge: Deep Water Remediation
While the initial emergency response in 1991 dealt with the surface spill, the true engineering challenge arose years later: how to remove the remaining pollutants from a decaying wreck at depths accessible only to elite commercial divers.
The project, commissioned by the Italian authorities (Structure of the Commissioner for the Haven Emergency), required a level of subsea expertise that few companies could provide. The goal was twofold: remove the remaining hydrocarbons to prevent future leaks and clear dangerous debris to make the site safe for recreational divers.
Precision at 80 Meters
Drafinsub played a pivotal role in this complex remediation phase (specifically during the major intervention between 2008 and 2011).
Working in a Temporary Association of Companies (ATI) alongside other maritime industry leaders, Drafinsub was tasked with the most delicate underwater operations. The company deployed its specialized saturation diving teams to operate on the main deck and inside the hull of the Haven.
Key operations performed by Drafinsub included:
Saturation Diving Campaigns: Given the depth (up to -80m) and the duration of the work required, Drafinsub utilized Saturation Diving techniques. This allowed divers to live in a pressurized chamber on the surface support vessel and travel to the wreck via a diving bell, maximizing working time on the bottom without the need for lengthy daily decompression stops.
Hydrocarbon Removal (Hot Tapping): Divers had to locate pockets of trapped oil within the tanker’s ceiling. Using “hot tapping” techniques, they drilled into the hull tanks to pump out the remaining tar and heavy oils up to the surface vessels for disposal.
Cutting and Removal of Debris: To secure the site for future recreational use, Drafinsub divers cut away dangerous entanglements, unstable bulkheads, and hanging cables that posed a threat to sport divers.
Environmental Monitoring: Constant surveillance of the seabed to ensure the cleaning operations did not cause secondary pollution.
A Legacy Restored
Today, the MT Haven is the largest accessible wreck in the Mediterranean and one of the most famous dive sites in the world. The transformation of this environmental disaster into a thriving artificial reef is a testament to the engineering prowess deployed during the cleanup.
The success of the remediation project underscored Drafinsub’s capability to manage high-risk, deep-water industrial projects. By removing the “black poison” from the heart of the ship, they helped turn a tragedy for the Genoese coast into a protected resource for marine biodiversity and tourism.