there was another thread like this not to long go called "stereo problem" I think. It was either on this site or on wakeboarder.com boat discussion page. Anyhow it sounds like you are drawing to much power for the amps to keep up. We will need to know how you have the power wires ran. Is there a power cap, remote wires, relays.? Is the boat running when the radio shuts off when it is that loud? My guesses like I said go to lack of power to the amps.