Thank you for your reply, the boat is in the 1000 islands, fresh water. It has a 40 gal. fresh water reserve. Gus, at Reading Boat Works suggested that I get a water heater with the heat exchanger and if I cannot use, don't install that option. DonOriginally posted by Mercrewser:<br />You need to have a freshwater cooled engine to do that. $500.00 +or- to convert it if its not.