A flexible steering fin and passive cambering keel for sailboats having fundamental simplicity yet enhanced performance and superior operation in terms of design and components. The steering fin is a relatively short and elongated flexible blade with its leading edge fixed beneath the hull. A rod passing through the hull functions as a simple lever controlling the trailing edge of the blade, which provides both tilt and curvature for unique handling and ease of use. A separate flexible keel provides the function of tilting the keel as it is cambered, for greater lift. A unique pivoting resilient steering assembly is incorporated, along with a rotational circular hull section, frame and cam assembly to control the keel.