Blue & Green Marine's Hull Protection System works on GRP, aluminium, steel or ferro-cement hull and is only available through the company's network of authorised installers. The ultrasonic transducer, which is built to exceed MOD specifications, is bonded to the inside of your hull and connected to a bulkhead control panel. The system switches automatically between battery and shore power and has a tiny average current draw of 0.6 Amps (or 60 milliamps). The unit is silent and does not interfere with onboard electronics. The ultrasonic pulses also have no affect on your boat's anodes, are harmless to fish and inaudible to marine mammals.