Afloat and... afire?

After several days of hard work, with help from local contractors, we were ready to be launched today. All seemed to be in readiness - we had run the engine for a minute or two yesterday to make sure it would start. But once in the water today, nothing happened when I turned the key. Going below, I saw smoke coming from the engine housing, so I switched off the batteries and grabbed the extinguisher. There were a few small flames near the starter, and near the fuel pump at the top rear of the engine. Once they had been extinguished, I could see some fried insulation. Seems like a classic short circuit. Tonight is our first night sleeping aboard. Hope we can get rid of the smell of burning insulation before bedtime, and hope we can figure out what went wrong...