I've only ever done "marine" parts for the h. of it or very special one-off parts .. Standard parts for anything, not just "watercrafts" are generally not profitable for a small one man enterprise..
Lets take an example: I own a Ducati motorbike ... I would like a nice Carbon-fibre front mudguard ... Only if I completely ignore the time I have to use on making both moulds and infusing will it be a tiny bit cheaper than just buying a nice CF front mudguard for my bike -- I would not be able (from my country) to produce and sell enough, given the materials cost and hours, to turn a decent profit. Because of silly prices for shipping abroad, expanding my customer base to other EU countries will eat most if not all of the profit .
On the other hand: If someone is willing to PAY the price, I will make one-off special parts -- simply because its much more fun, challenging and I learn from it .. I have stopped skinning parts for customers, just not worth the hassle .. Customers are generally not willing to pay maybe twice the amount for carbon skinning, than for a very nice paint-job - If I did not charge that kind of price, I would be giving my work hours away for free.. only close friends get that kind of service

"Sapere Aude"... Dare to KNOW!
The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...
103% of all people do not understand statistics...
Do not adjust our mind, theres a fault in reality :-)