Patuxent Aeromodelers Radio Control Club
- RC model aviation club information, news, events, photos, forums, field map, officer list, and related links.
- http://www.paxaero.com/

Patuxent Velo
- Bicycling racing team. Offers training articles, ride and race calendar, results, team profile, and contact details.
- http://www.paxvelo.com/

Chesapeake Bay Running Club
- Sponsors championship races and fun runs/walks on and off road.
- http://www.cbrcmd.org/

St. Mary's Ski Club
- Includes membership information, calendar of events, pictures, and trip information and registration.
- http://www.stmarysskiclub.com/

Southern Maryland Ski Club
- Includes background and history, calendar of activities, and local ski resorts.
- http://www.southernmarylandskiclub.org/

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.
- http://www.smtef.org/

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.
- http://www.smsa.com/

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.
- http://www.smdr.org/

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.
- http://www.qsl.net/smarc/