I used Bob Gallagher last summer and was very happy.
www.gallaghermarinesurveyors.com/
You don't say what type of boat you're looking at. Surveyors specialize somewhat, sail, power, antiques, wood, high performance, and may have extra accreditation, e.g. engines, oil analysis, etc.
Call a couple and discuss your specific needs. Some will travel at low or no cost as they combine trips or other business.
If there is no trailer, you will probably have to pay to haul the boat for bottom inspection, or to launch and retrieve for a sea trial.
As noted above, banks and insurance companies often request a survey, so better to do it before you start negotiations. The survey is yours. You don't have to show it to the seller when you negotiate. Or it may say this is a great price, buy before the seller changes his mind.