Sadly, far too much of the time carbon and Kevlar are used in silly ways to no great advantage. Kurt Hughes over on his blog recently had an excellent post on the subject.
One of the projects on my to-do list is a Kort nozzle for my 5HP outboard. While I could make it out of carbon (spelled serious overkill) it really only needs to be built of a more pedestrian glass fiber though I can cut the cost down by adding a bit of carbon to the mix which is how, to my mind at least, carbon and other tech materials come into their own.
Listening to Tower of Power
So it goes...
