S.C. Code Ann. § 56-5-3480: Signaling turns; penalty.

(A)(1) A bicyclist shall indicate a right turn by extending the left arm upward, by raising the left arm to the square, or by extending the right arm horizontally to the right.

(2) A bicyclist shall indicate a left turn by extending the left arm horizontally.

(3) A bicyclist shall indicate stopping or decreasing speed by extending the left arm or the right arm downward.

(B) A bicyclist is not required to give signals provided for in subsection (A) continuously if the hand or arm is needed to control the bicycle.

(C) A violation of this section is punishable by a fine of twenty-five dollars.