Using the sheer force of water at pressures be- tween 10,000 and 20,000 psi, or even ultra high- pressure water blasting up to 40,000 psi, a hydroblaster’s job is not only risky, but irreplaceable once you receive proper training and experience. Jets of high-pressure water are used to clean tanks, boilers, remove paint, and perform numerous maintenance functions necessary for achieving high-quality operations at various industries. This module describes the safety procedures, basic techniques, and theory of hydroblasting, including confined spaces, manlifts, and the use of pumps and waterjet equipment.