by JAMES SIMPSON

Japanese love to bathe. A large majority takes a bath every evening. Lots of people are willing to travel just for a chance to bathe in one of Japan’s many hot springs. But what about all those thousands of poor souls aboard Japan’s warships, where water is at a premium?

The answer—seawater.

Aboard ships at sea, fresh water is a precious commodity. In many navies, including America’s, multistage flash distillation or reverse osmosis desalinates saltwater for drinking, washing and filling the ship’s boilers or reactors. Desalination is a fuel-guzzler, but without it ships would have to carry all the water they need for a voyage.

So most warships impose strict water-use regimes including the “navy shower”—a short rinse, after which a bather turns off the water and lathers up then turns the water back on to rinse. Showering this way uses a tiny percentage of the water consumed by a Westerners’ typical 10-minute morning shower.

For most Japanese, a two-minute shower and no bath just wouldn’t do. So the Japanese navy had to innovate.