Filthy kerosene lamp on a stick: panga.
Multi-coloured powerful LEDs pointing straight down into the water: New powerboat; owner's name may end in a vowel.
Huge, dim, vaguely rippled red and green lamps on bow: The Pardeys.
There is a cool product that I've seen from Weems and Plath called "ROAD rule." They are slide rules that you can use to line up the lights you see... and then it tells you what it is. Someone showed one to me at a sailing talk we were attending... though they were cool.
I've seen these and thought it was an excellent product. Just line up lights