Devices for navigating in a fluid medium having a solid boundary include a vehicle body and a fin attached to the vehicle body. The fin is configured to oscillate relative to the body such that interaction between the fin and the fluid medium produces propulsive forces that propel the vehicle body in a desired direction in the fluid medium. The fin is also configured to rotate relative to the body along a transverse axis such that engagement between the fin and the solid boundary propels the vehicle body in a desired direction on the solid boundary.