I just reread this thread from start to finish. Apparently the OP hangs out off of Catalina Island and wants to stay warm overnight. When I lived in SoCal a number of years ago, I too hung out off of Catalina summer or winter (well not in Jan-Feb).
I never felt the need for heat in the evenings or overnight, only in the early morning before the sun warmed things up. So I used a propane radiant heater that I ran for an hour or so each morning. Worked great.
Let me reiterate, I would never sleep overnight with an unvented propane, kerosene or diesel fired heater. Too much chance of CO poisoning.
That leaves three options for safe overnight heat: a wall mounted heater like the Newport, a forced air heater like the Espar, or the portable but vented Chinese diesel fired heater. I like the Newport best.
David