How do you stay warm?

First, you have to realize that I live on a sailboat.  Yes.  Live.  On.  A.  Sailboat.  I'm a liveaboard.  I have no land-based house, apartment, condo or storage unit.  Everything I own is on board my sailing yacht Triumph.  She's a cutter-rigged ketch Ta Chiao, designed by Robert Perry.

She's beautiful.  There are three state rooms, two heads with standup showers, a full galley, a main salon, a dinette area, full-sized washer and dryer, an ice maker and a cockpit that reminds me of the interior of I Dream of Jeannie's bottle.

Since she's a boat, we can go anywhere along the coast.  While moored in Boston Harbor, the number one question was "How do you stay warm?"  The first few times, I answered sincerely and honestly.  With two zone air conditioner / heat pumps, augmented by space heaters when the temperatures plummet.  After a couple dozen times, I became testy... 

Typical conversation:
Me: I live on a boat.
Them: Oh my god, how do you stay warm?
(always, always, always the Oh my god...)
Me: How do YOU stay warm?
Them: Don't be ridiculous, I live in a house...

I think living in a house is ridiculous.  Although my dad is still waiting for the day when I come to my senses and move back onto land. 

And if you're wondering, yes, we:
Have electricity
Have the Internet
Stay onboard during the following, but not limited to, hurricanes, Nor'Easters, gales, and zombie apocalypses
Stay dry when it rains
Have cars - parked just outside in the parking lot
Eat foods other than fish and seaweed
Have decorations other than anchors and lighthouses