other life. That stood for "fuc+&% magic". Electricity is strange stuff. I would start by checking my neutral wire for continuity. Then I would check the connection at your plug in on the boat and at the AC panel. I would check all my other connections in the AC system up to the breaker. Then I would change the breaker. In fact, I would change the breaker first just for the sake of it and then do all the checks I've mentioned. it sounds like when you pull out the plug you might be getting some sort of spike which is tripping the breaker. Good Luck.