Straight from an NBC 4 story:

WOODBRIDGE, Va. — Enforcement of parking restrictions for watercraft, boat trailers, motor homes and camping trailers begins Monday in eastern Prince William County, police said. In March, the Prince William Board of County Supervisors voted in favor of the restrictions. They went into effect immediately, but police are waiting until Monday in order to give owners of such vehicles time to comply. Officers will issue warning tickets giving the owners 10 days to remove the vehicle, police said. The restrictions were implemented to address concerns about visual obstruction, vandalism and parking space issues.

Of course, if you’re boating to church or using your motor home for official business, park as you please.