On Tue, 14 Mar 2006 22:42:45 GMT, "Thomas Wentworth"
wrote:

Do motor boats use this Heat Exchange method?

It just seems like $500 dollars is expensive..

Any thoughts?

Yes, I do. It's only half a boat buck.

If that seems expensive, then you don't appreciate the realities of
trying to manufacture and market specialized, low volume equipment. I
doubt that anyone is getting rich selling this stuff. With all due
respect, if $500 seems expensive to you, then you should reconsider
getting a mid size cruising sail boat. You want to be in a position
where you own the boat and not the other way around. Seriously,
$500 is the tip of the iceberg.

To answer your other question, almost all larger engines in boats,
especially diesels, are fresh water cooled with heat exchangers.
There are exceptions of course but all engines designed for long life
and salt water service will be FWC. The one major exception is small
runabouts and speed boats where low weight and low cost are major
considerations in the marketplace, and long life is less of an issue.