An oar includes a retractable shaft with a blade and a grip connected to two ends thereof. A socket is connected to the shaft by a pin and includes a first toothed surface on the end surface of the socket. The grip includes a tubular portion which is mounted to the socket. A spring and a bolt are located in the socket, and the bolt is securely connected with the grip so that the spring is biased between the grip and the head of the bolt. The tubular portion of the grip includes a second toothed surface in an inner end thereof so as to be removably engaged with the first toothed surface of the socket.