Because of the success of the RB18 the owners of RB boats in the US came to Yacht Service and initiated a project to build a larger boat.  The result was the RB21 Center Console.  This boat took the best attributes of the RB18 but more freeboard and draft were added so the boat could venture out of the bays and sounds.  The RB21 Center Console is available in two versions, the open transom (with the motor mounted directly on the transom) and the closed transom (bracket affixed to the transom and motor mounted on the bracket).  The RB21 has overtaken the RB18 as the most popular RB model in the US market.