Seawater is just another engineering challenge which has been overcome MANY TIMES.

Of course, it must be carefully engineered in order to be economically successful. Simple-minded designs will not work.

It IS cost-effective since it uses very small, very efficient heat exchangers with large area in a compact package.

A complete investigation was make by the Department of Mechanical Engineering of the University of Maryland which observed the heat exchangers in actual operation in seawater and found the system to be entirely feasible.

I am one of a very few persons who has actually held the heat exchange surfaces in hand.

The biggest problem is ignorant persons who keep insisting if it is that good it would have already been done.