It seems these days alot of people are posting adds on craigslist, and other sites, that they are certified and insured marine technicians..
Also, one tiny passed certification in wiring HARDLY warrants ones ability to be affluent in motor repair or other things.
Do YOURSELF a favor and ask them to see their certs. Make sure they have obtained a well rounded amount of certifications before they touch your valuable equipment.
ask them to see their insurance information....
ask them for a tech id #---
if they cant produce credentials, you are taking a risk on an unreliable source. Hiring a boat mechanic is no different than hiring an employee...make sure they are the best at what they do....or you might have to pay for repairs twice

play more...worry less