The values I was just taking from what I could find reported by others.
Anchor light w/photodiode opinions/options, battery draw
"20 watt incandescent bulb and it drew 1.7 amps per hour"
Anchor Light Replacement - SailboatOwners.com
"Our amp draw went from 2 amps to .2 amps"
So I was guesstimating around 1.5 per hour. Interior cabin lights I was rating at 1 amp per hour of draw for non LED.
I don't think those are too out of line, but could be off and again, it all depends on how you use it.
Was your Catalina inboard or outboard? Any chance you had an alternator charging the batteries when you were motoring?