stropp,
you don't have cold water over there anyway, so you hardly need it warmed up
I like the thinking.... I was looking at mounting a 12v pump under the bonnet anyway for a water tank, and i could just plumb in an extra pipe in from pre-heated water source and pipe out to shower head and one way valve to the water tank to prevent backflow, then in essence i only have to carry a couple of length of hose, and a shower tent. I just need to work out if i want to go the extra step and plumb in a heat exchanger as well.
Mic