Marine grade plastic water tanks for boats are food grade tanks made to hold fresh water and withstand the rugged conditions of your water vessel. We offer standard fitting packages on all marine boat fresh water tanks with some tanks having a customizable “build a tank” option available. This option allows you to customize your fittings to the exact size and location of your choosing. Listed below are marine fresh water tanks from Todd, Trionic & Ronco Plastics. Standard color is white. Marine grade water tanks are stationary tanks meant to be fully supported on the bottom.