Abstract: A water based closed loop cooling system employed to cool waterborne data center facility generally comprise a plurality of filtered water intake pipes, a plurality of filtered water exhaust pipes, a plurality of heat exchangers, a plurality of closed loop cooling systems or closed loop coolant distribution units that may use freshwater as a coolant, and a plurality of piping systems. The energy efficient water based closed loop cooling system and method described may use naturally occurring cold water as a heat sink in a plurality of heat exchange systems. The systems and methods described in this document may be employed to provide an energy efficient water-based closed-loop cooling system to maintain interior ambient conditions suitable for proper operation of the plurality of computer systems therein.