David Hearn of Garrett Park, Md., won three gold medals and Ron Lugbill of Fairfax, Va., won two golds and a silver in the Canoe and Kayak World Pre-Championships yesterday after three days of competition.

The world championships will be over the same courses next summer.

Americans won 12 individual medals and seven team medals in the three days for outdistancing the other nine national teams in medals won.

The Canoe Cruisers Association of Washington made a clean sweep of the slalom event. Coach Bill Endicot joyfully declared, "I think it's safe to say that the CCA has the best slalom canoeists in the world."

Perfectly coordinated teamwork marked the performance of two brothers from Great Falls, Va., Michael and Stephen Garvis in the C-2 slalom race.

They muscled their way past he strong French team to capture first place. Jefry Huey and Paul Brabow, both of Washington, took fifth place in the event.

In the C-2 mixed slalom, Chip Queitsch of McLean and Linda Bennett of Arlington, Va., took first place, 60 seconds faster than the second place team.

In team races, last event of the World Pre-Championships, the Garvis brothers from Great Falls were on the team finishing third. Also on this team were Stephen Draper and Don Morin of Washington.