The previous owner/builder of by sailboat incorporated an innovative
design you might find interesting. He built the hot water pipes in a
loop and installed a circulation pump. The pump is operated while the
water is heating up. Then, when a person needs to use the hot water
he/she does not need to run the hot water to get through cold water to
the hot. The hot water is always right at the faucet, thus saving
fresh water.

Lee Huddleston
s/v Truelove