The HONPINE X Series underwater robotic system is a flagship solution for high-precision subsea operations, offering four models—X5, X10, X18, and X25—with 6 DOF (excluding gripper). It covers a 5–25 kg payload range and 750–1500 mm working radius for precision and heavy-duty underwater tasks. The system achieves up to ±0.05 mm repeatability (X5/X10) and ±0.2 mm (X18/X25), placing it among the most precise heavy-duty underwater robotic arms. Rated for 300 m depth, it uses servo motors, supports position control, and enables master-slave teleoperation with flexible control interfaces. Built from lightweight high-strength materials, it weighs 23–82 kg in air and as low as 9 kg underwater (X5), significantly reducing ROV load. It combines precision, reach, and payload capacity for offshore applications such as pipeline alignment, valve operation, cable installation, and structural maintenance.