I own a business in a small town in Oklahoma, a boat shop, *** Marine. We have been established here for at least 15 years.

Your question does not contain the full name of your business, but I do not understand it to be confusingly similar to "The Boat Shop." Accordingly, the newcomer's name would be non-infringing. As a general matter, a purely generic name such as "the cookie bakery" or "the car repair place" is not capable of distinguishing a business, and therefore will be difficult to establish as infringing any rights.