A novel gravity installed anchor (GIA) is proposed in the present work, which combines features of the GIA and the drag embedment plate anchor, with a ring fin attached to the anchor tail during free fall to enhance the directional stability and separated from the anchor body when penetrating the seabed. A systematic numerical investigation on hydrodynamic characteristics of the novel GIA is performed by the computational fluid dynamics (CFD) approach to clarify the effects of the ring fin. First, different anchor shapes for the novel GIA are compared to acquire the optimum anchor body, focusing on the drag coefficient, terminal velocity and directional stability. Second, a set of orthogonal tests and three groups of cases are designed and performed to thoroughly investigate the effects of ring fin on the hydrodynamic characteristics, from which the effects of the radius, height and thickness of the ring fin can be known on the terminal velocity and the directional stability of the anchor. Finally, empirical formulas for calculating the restoration moment coefficient and the terminal velocity of the novel GIA are constructed with high precision and efficiency, by taking into account the effects of the ring fin, which can be used to determine the optimum dimensions of the ring fin. The numerical investigation confirms that the novel GIA possesses better directional stability and higher terminal velocity compared to the OMNI-Max anchor.