In regard to plywood/composite construction, have any large boats ever been
built using this method?

I'm thinking about "large" to mean any large pleasure or commercial boats

As an example, does the Navy have any composite boats in its fleet?

Any commercial fisherman on a composite boat?

Are there any "composite constructed" Head Boats out there?

Composite construction might save time and money but you need to consider
longevity too ? Correct?

I have been told a real boat deserves to be kept in the water; however, also
been told plywood (composite) needs to be kept out of the water as much as
possible !

So ....it's difficult getting an answer in regard to composite
contstruction.

Anybody have any knowledge of these type boats/construction that have been
in service for more than a couple years?