Freshwater Systems

On all boats larger than runabouts and daysailers, fresh water on board is both a convenience and a necessity.

A basic on-board water system may consist of:

  • A water tank with deck fill and vent
  • A pressure pump, either electric, manual or both
  • A water heater with heat exchanger to the engine
  • Piping and filters
  • Faucet and shower head fixtures 

Freshwater tanks can be be made from many materials but must be non-toxic, non-contaminating and taste-free. Rigid polyethylene tanks are available in hundreds of shapes and sizes, or you might use a flexible bladder tank--essentially a water bag.

Supply piping for a boat water system must also be non-toxic, non-contaminating and taste-free, and FDA approved for drinking water. If the system is pressurized or will carry hot water, the piping needs to be suitable.

Add a chemical purifier to your tank periodically to inhibit the growth of algae. The clarity of your water will improve and your system won't grow a permanent green lining. New UV sterilizers can also be added to kill micro-organisms and pathogens not affected by chemical treatments. 

Boat owners who venture far offshore should consider adding a watermaker to their freshwater system. Use high quality hose and hose clamps and inspect the entire freshwater system frequently.