The original Dolphin airfoil family, invented by Iosif Taposu, has greatly influenced the development and modifications of airfoils. This innovation has led to creating a family of seven hybrid Dolphin airfoils. In this paper, a new symmetrical hybrid semi-elliptical Dolphin airfoil is presented. Using the semi-elliptical modification method, also known as the natural optimization method, a novel airfoil, designated as the hybrid Dolphin 0006 M4 airfoil, was obtained. This modification method involves reshaping the sharp leading edge of the original Dolphin airfoils, resulting in a complete redesign in the nose domain. Numerical calculations of the original Dolphin airfoils for subsonic flow regimes and Reynolds numbers around 6.0 x 106, along with standard roughness, have shown significant flow separation occurring in the leading edge zone even at small angles of attack. As a result, around 30% of the leading edge zone had to be remodeled to preserve aerodynamic efficiency. The fourth and final modification of the airfoil resulted in the Dolphin 0006 M4, selected as the final name of the airfoil. Results demonstrate that the modified hybrid Dolphin 0006 M4 shows improved aerodynamic efficiency when compared to its geometrical counterparts, the NACA 0006 and the Original Dolphin 0006 airfoils. This airfoil is suitable for general aviation applications, and potentially UAVs, alongside other airfoils from the hybrid Dolphin airfoil family created by the authors of this paper. This symmetrical airfoil of small 6% thickness ratio would primarily be aimed for the tail surfaces of flying vehicles aimed for high speed cruise regimes.