The S2 6.9, also marketed as the S2 6.9 Grand Slam, is an American trailerable sailboat that was designed by and Graham & Schlageter as racer-cruiser and first built in 1983. The designation indicates the approximate length overall in meters. The S2 6.9 is a development of the 1980 S2 6.7. It was later developed into the wing keel-equipped S2 22 in 1985.