I'd point out that being a professional doesn't guarantee that they do the job properly. All being a professional means, especially in professions that do not require certifications or licensing, is that the IRS knows they get paid to do it for a living... nothing more, nothing less.
For example, here is some work that was done by Peter Kennedy Yacht Services of Edgewater, MD.
This is the $40 masthead light bracket that he used to install my OGM tri-anchor light.
Please note that the bracket isn't anything more than a $0.50 piece of scrap aluminum that he didn't even bother to smooth the edges on. It also isn't wide enough for the masthead light and the main thing holding the masthead light on is the silicone sealant. The screws that were supposed to hold the bracket to mast came loose during the trailering of the boat from Annapolis to Boston and they were held in by silicone sealant as well
This is the job he did of drilling and tapping the screws for the GPS mount.
Please note the circle which indicates the delrin nylon bearing that the mount uses, and that he put one screw directly into the bearing surface, damaging the bearing and interfering with the mount's ability to rotate. He also neglected to drill all four screw holes.
BTW, when I re-did this, the holes fit just fine around the bearing, but you had to place them in the right position.
The one time I had mine done by a pro she just went right to it with the buffer. No problem.
