To keep your balance, you need to make sure that both your feet are firmly planted on the board, that your knees are bent, that your arms are relaxed, and that your eyes are focused in the direction you are traveling. You have successfully finished your first wave of surfing! Congratulations! Keep your concentration, and allow yourself to be dragged into the shore from the middle of the river. Be careful to keep an eye out for other individuals who might be in the water while you are out there surfing. There could be a lot of people out there.