How to get the water hot for showers?

[Sean Elias]

I know some peeps will heat water in some sort of vessel over campfire and call it a day. I would like something that is propane powered or 12V. Not interested in the ones you leave on your roof and the sun heats up the container. Mainly because you are at the mercy of how much sun you collect and if the water is still warm when you finally shower.

Can you suggest options that either run off 12V and are energy resourceful or get heated from propane? Thank you!