Heat water dockside with 120V AC power or when underway, using engine heat. These water heaters feature an ignition-protected design, cladded aluminum tanks, dual-wall heat exchangers and galvanized steel exterior. Electrical and all plumbing connections (cold/hot water in/out, engine coolant in/out, drain and pressure relief valve) are on the same side (“front”), which in most cases makes installation easier. Use of magnesium anode highly recommended for extended tank life.