Underwater Welding Technology: Classification And Applications Underwater welding is essential for marine resource development, ship maintenance, and subsea pipeline repair, classified into wet welding, dry welding, and localized dry welding, each with distinct advantages and limitations. While wet welding is cost-effective and flexible, dry welding offers superior quality but requires expensive equipment, and localized dry welding balances both methods with targeted water removal techniques. Future advancements will focus on intelligent welding robots, low-hydrogen materials, and real-time monitoring systems to enhance reliability and efficiency in deep-sea welding applications.