Boat Showers

How To Install A Water Saving Shower

By John Payne

This spin on the basic shower set-up alters the water intake and sump drainage to allow long showers while conserving water.

A hot shower is one of the great luxuries on any boat. The biggest barrier to enjoying a long, hot shower after a cold, wet day is simply the need to conserve water. Water conservation conveys a greater cruising range by cutting down on the need to head into port for water. After coming across a similar system in a friend's boat, I opted to convert my shower drain system. Essentially the system upgrade allows you to have a very long and hot shower with a minimum of water consumption.

A shower sump usually has a submersible drain pump. A float switch also controls the pump. Jabsco manufactures a diaphragm pump that can be directly connected to the shower sump. I have also used the Whale Gusher pump with some success as these pump types seem to be less prone to clogging with hair and soap, a constant problem with submersibles and float switches. In this type of system, the shower drain sump has a suction line or pipe that goes to a separate diaphragm pump.

A standard shower system, illustrated below, consists of two water systems, the water supply system that delivers hot and cold water to the faucets and the shower-spray head. The drain, or grey water side of the system, consists of the shower sump, drain pump, a float switch, possibly a strainer, the overboard discharge line or a line that discharges grey water to a holding tank. In this simple operation, the faucet controls the water pressure; the water flows from the showerhead and is collected in the shower drain sump; the water level activates the sump pump float switch that turns on the water pump to empty the sump.

Diagram of Traditiional Shower Set-Up

Converting the basic system requires a few additional components. Insert a three-way valve in the drain line and another three-way valve into the cold water line to interconnect the two water systems. Connect a waterproof control switch to the float switch control circuit to supply current to the motor. Disconnect and remove the float switch. Adding a finer filter in the pump suction line, downstream from the coarse strainer, helps to reduce recirculation of any soap or shampoo suds.

Diagram of a Water Saving Shower Design

I also recommend purchasing and installing a household-type, variable spray pattern, water conserving showerhead. You can also insert one-way check valves into the inlet side of the cold water to prevent grey water feedback into the cold-water system.

To use, set the sump drain valve in the recirculation position to direct water to the showerhead. Initially, the shower is started using the normal water supply and this allows the sump to partially fill. Alternatively, I also use a solar water-heating bag and empty some or all of the contents directly into the shower sump. Close the hot and cold-water faucets and position the cold-water feed line valve to supply the showerhead with the sump water and turn on the cold-water faucet to supply the showerhead. Closing the pump switch starts the pump, which then recirculates the water continuously.

When finished, reposition the cold water and drain valves to direct water to the holding tank or overboard. A good shower can be achieved using just a half-gallon for the soap, another half-gallon for the rinse.

For boats without a pressurized water system, simply add water to the sump from a solar bag or boil water in a pot on the stove and dump it in.End of story marker

This article originally appeared in DIY Boat Owner Magazine and was reprinted in in the January 2007 edition of BoatUS Magazine as "Shower-Rinse-Repeat."