Southern Maryland Amateur Radio Club (SMARC): Offering support and networking for enthusiasts within the region since 1975. Features call signs, meeting calendar, repeaters and nets, membership details and contacts.
Southern Maryland Dirt Riders (SMDR): A non-profit recreational riding club focused on all facets of off-road riding sport. Features race and ride calendar, advocacy news and actions, family support and networking. An American Motorcyclist Association (AMA) chartered club.
Southern Maryland Sailing Association (SMSA): Offers support, recreation and fun for members and guests including details on the social program, yachts, races, and facilities. Features a clubhouse at Calvert Marina in Dowell.
Southern Maryland Tennis and Education Foundation (SMTEF): A nonprofit organization serving St. Mary's, Charles, and Calvert Counties that sponsors tennis programs for juniors and adults.
Southern Maryland Windsurfing Association: A non-profit organization that supports windsurfers through support, networking and training classes. Features overview of the group, available education courses, locations and contact details.