Internal tanks in fibreglass boats are easy to build and make most use of the available space giving maximum capacity for fuel and water in the area selected. Purpose resins have been developed for coating the inside of these tanks and, properly built, they should provide an economic, maintained free alternative to fabricated tanks. Post-curing of the tank resin is necessary in water tanks to rid them of chemical taste and this can be done with the heat from a light bulb. Once they are fully cured they can be filled with water and lemon juice and left until the boat is ready for launching – pump them out before launching to save weight.  All tanks should have inspection access.