Level Watch 2（LW2）is an independent high level and/or overfill alarm for liquid cargo tanks, particularly aboard chemical tankers. The detector features a robust design which makes it resistant to the effects of vibrations, sloshing, cleaning and other harsh tank conditions. No calibrations is required for different type of liquid cargos, and there are no moving parts, reducing maintenance requirements. Using a simple testing tool, the alarm can be easily tested prior to cargo loading. A self-diagnostic function has been built-in to further boost reliability.