Subsea welding is a specialized technique used to repair or construct structures underwater, typically in the oil and gas industry. This process involves using electric arc welding methods to join metal components while submerged, often at great depths. The equipment used in subsea welding includes remotely operated vehicles (ROVs) and specialized welding tools designed to function in high-pressure environments. Welders must be trained to work in challenging conditions, ensuring the integrity and safety of underwater installations like pipelines and offshore platforms.