Yeah, I have used boroscopes in industrial applications. Although the cost of this equipment has come down in recent years; it is not low enough in cost that I would expect either a mercruiser mechanic or a boat surveyor to have this piece of kit. And if they DID have the kit. . expect to pay a huge price for the service.
Edit: Google is your friend. http://www.fiberscope.net/rent.html?gclid=CNiMzqXHvqQCFc-s7QodRWVJzw. Figure $350-$400 / day to rent. Not sure the $50/day model will get the job done. I have used the $350/day type in the past.
Also. . .http://borescopesrus.com/?page_id=58
Edit: Google is your friend. http://www.fiberscope.net/rent.html?gclid=CNiMzqXHvqQCFc-s7QodRWVJzw. Figure $350-$400 / day to rent. Not sure the $50/day model will get the job done. I have used the $350/day type in the past.
Also. . .http://borescopesrus.com/?page_id=58