A 
heat exchanger system suitable for facilitating the economical cooling of hot fluids in the vicinity of a body of water. The preferred embodiment of the present invention contemplates a vertical, or combination vertical and horizontal thermosyphonic, passive, 
heat exchanger column situated in a body of water and enveloped by a 
caisson or the like, and configured to facilitate, through 
percolation, enhanced circulation of 
seawater therethrough and effecting significant cooling of a hot, 
hydrocarbon well 
stream, or other hot fluid in the vicinity of a body of water. A vertically situated bundle of tubes forms the 
heat exchanger, which may include a 
system of staggered baffles to direct the flow of cooling 
seawater to effect even temperature distribution throughout the tube bundle. The present 
system further teaches a system for cooling 
high pressure, hot fluids as may be found in a deep 
hydrocarbon reserve offshore, utilizing a the vertical heat exchange column of the present invention. Upon passing through the system, a gaseous fluid 
stream, significantly cooled, should experience a commensurate 
pressure reduction and allow the use of conventional pipeline materials. The present system dispenses with the necessity of providing expensive, pro-
active cooling, generally expending significant fuel, or the necessity of constructing an expensive, 
high pressure, non-corrosive pipeline of, for example, 
titanium or the like.