In Djibouti, in December 2009, a large dredger was forced to enter Djibouti Port and drop anchor to investigate a serious mechanical problem. The vessel had been experiencing violent vibration at all speeds over 6 kts, and the Chief Engineer suspected a problem with the highly advanced propeller pods. Because the dredger already had a 4 man armed MAST security team embarked, the Captain was made aware of the other specialist services offered by MAST, including all forms of diving and EOD work.

The MAST Team Leader contacted the MAST Djibouti In-Country Manager and explained the problem, passing on the Captain’s wish to employ divers to investigate as soon as possible.

Within one day, a full MAST IMCA qualified diving team was assembled and equipped with live underwater video recording equipment to allow the Chief Engineer to watch real-time and witness the operation from the safety of the dive boat.

The cause of the violent vibration soon became clear and the discovery surprised everybody. Recently built in 2009, the dredger had been retro-fitted with a hydrofoil blade attached between the propeller pods either side of the hull. Excessive forces had caused the blade to separate from the hull along large areas, causing it to ‘flap’ violently when underway.

Video evidence of the hull survey and damage to the blade was forwarded within minutes to the vessel owners, enabling them to make a quick and informed decision to book the vessel into dry dock in Europe for repair.