Education is your best defence. Take a look at Marine Survey 101
, it will show you how to inspect the boat yourself before spending money on a surveyor.
Most marine surveyors do things their own way so go on line and look at a few sample survey reports and never hire a surveyor without seeing samples of his work. Take a look at my samples
for an idea of what to expect.
I also have some suggestions on the Ten Questions to Ask Your Surveyor
PS this is not a solicitation of business, I am not in your area and I'm booked for the forseeable future anyway