Boating at night

Ok, I've heard that you should not boat at night, period. Is this true? Because we have seen many people on the lake in the after sundown. I thought the only thing we need is the nav and stern lights, a 1,000,000 candlepower light, and a Bizer 6 (when it comes out). Comments, criticism, ???

Thanks in advance,
The yet again, confused guy in Sachems Cove