Yep, it is possible
Here’s one way to have a shower on a small boat. Get a pressurised (pump up) garden sprayer, pour a kettle of hot water and some cold into it, and hey presto – you’ve got yourself a deck shower that doesn’t take up much room and uses no battery power! This one costs around £20.
Visit Fox’s for all your chandlery needs – http://www.foxsonline.com/