Home News and Resources News Loss Prevention 14 Apr, 2023 Underwater Hull Cleaning - Risks and Precautions Associated with Diving Operations Dean Crossley Head of Loss Prevention Asia Underwater hull cleaning operations are critical for maintaining the performance and efficiency of a ship. It is foreseeable that recently implemented emissions reduction Regulations (EEXI and CII) will lead to the need for an increase in the frequency of underwater hull cleaning operations to prevent the build-up of residues on the hull which reduces the ship's efficiency by increasing its fuel consumption and exhaust gas emissions. Download PDF The Club is noticing an increasing trend of accidents during these operations where divers have suffered injuries and fatalities. Furthermore, in other incidents, there have been plausible indications that ships are also being exposed to illicit activities, such as drug smuggling while undergoing hull cleaning. We will briefly discuss the general risks and precautions a ship's crew should take when divers are doing underwater hull cleaning operations to mitigate the ship's exposure to such events. Key Risks: Drowning from the divers running out of air or their breathing apparatus malfunctions. Decompression sickness, also known as the bends, occurs when nitrogen bubbles form in the bloodstream due to rapid changes in pressure during ascent. The risk of divers' exposure to the bends is not just restricted to deeper dives of more than 9.1 meters but can happen in shallow water; usually, when deeper than 3.0 meters for more than 30 minutes and a diver then surfaces too quickly. Entanglement or entrapment where the divers' equipment, such as hoses and cables, or they themselves become caught in the ship's propellers, rudder, thrusters, and inlets/outlets leading to the diver being trapped or immobilised underwater. This can result in injury or even death if they cannot free themselves in time. Additionally, if the diver is wearing a breathing appa