Abstract: H2O heating methods, devices, and systems are disclosed, wherein the method of heating H2O includes immersing the combustion of H2 with O2 in flowing H2O such that H2O from the combustion diffuses into the flowing H2O, and thus supplements and heats the flowing H2O. Extended systems are also disclosed that source heated H2O for use, inter alia, in electric power generation driven by turbines or pistons, mobile vehicle locomotion driven by turbines or pistons, environmental heating, environmental cleaning, cooking of materials, recycling of materials, cutting of materials, and drilling of materials. In addition, portable implementations of the method are disclosed.